Showing posts with label Behind the Headlines. Show all posts
Showing posts with label Behind the Headlines. Show all posts

Thursday, October 11, 2018

Behind The Headlines - Young people turning their backs on alcohol

What is Behind the Headlines?
Each day the NHS Choices team selects health stories that are making headlines. These, along with the scientific articles behind the stories, are sent to Bazian, a leading provider of evidence-based healthcare information. Bazian's clinicians and scientists analyse the research and produce impartial evidence-based assessments, which are edited and published by NHS Choices.

Wednesday October 10 2018

"Shunning alcohol becomes 'mainstream' among young people as a third are now teetotal," reports The Independent.

A study involving nearly 10,000 young people in the UK found that the proportion of 16- to 24-year-olds who say they never drink alcohol rose from 18% in 2005 to 29% in 2015. The study also found that young people who did drink alcohol were drinking less nowadays and that binge drinking rates were falling.

The researchers said the drop in numbers of young people drinking suggested a shift in attitudes towards alcohol. They say this could be due to increased awareness of the health risks of alcohol, as well as changes in the way young people spend their leisure time.

The researchers observed a decrease in drinking in most groups of young people, including those in employment, in education, and with generally healthy lifestyles, and across all income groups.

However, there was no decrease among smokers, some ethnic groups and people with poor mental health. This may indicate a need to reach out with more support to certain groups.

Current UK guidelines advise men and women to drink no more than 14 units of alcohol a week; equivalent to 6 pints of average-strength beer or 10 small glasses of low-strength wine.

Find out about calculating units of alcohol.

Where did the story come from?
The researchers who carried out the study were from the Department of Epidemiology and Public Health, University College London.

The study was funded by grants from Alliance House Foundation, an organisation that promotes "temperance" or not drinking alcohol. It was published in the peer-reviewed medical journal BMC Public Health and is free to read online.

The story was widely reported. The Telegraph is one of several media outlets that speculated about the reasons for the drop in drinking, suggesting in its headline that "millennials are shunning alcohol" because they think "getting drunk is no longer cool".

But the study didn't actually look into the reasons for the decrease in drinking. More research is needed to investigate the reasons why young people are less likely to drink alcohol.

What kind of research was this?
This was an analysis of repeated cross-sectional surveys of people aged 16 to 24 in England.

The researchers wanted to see how alcohol consumption had changed over time among young people in different subgroups. They also wanted to see how the increase in non-drinking related to the amount of alcohol consumed by those young people who did drink.

Cross-sectional research shows a snapshot of people's behaviour at any one time. Although behaviour can then be linked with factors such as income levels or health habits, we cannot tell from cross-sectional research what causes the behaviour observed. In other words, this study can't tell us what's causing more young people to abstain from drinking.

What did the research involve?
Researchers used data from the Health Survey for England 2005 to 2015, an annual nationwide survey that asks questions about a wide range of health behaviours. For this study, researchers looked only at information from the 9,699 participants aged 16 to 24.

People were asked whether they drank alcohol. If they answered no, they were asked if they had ever consumed alcohol, had previously drunk alcohol or occasionally drank alcohol.

People who said they did drink alcohol were asked if they had done so in the past week, and how many units they had drunk on their heaviest drinking day.

The researchers also looked at:
body mass index (BMI)
smoking status
fruit and vegetable consumption
physical activity levels
wellbeing and mental health
whether the participants had any long-term illness

They looked at the results broken down by:
age group (16 to 17 or 18 to 24)
gender
ethnic background
region where participants lived
whether they lived in a town, city or village
deprivation level of their local area
household social class
whether they were in full-time education or employed

What were the basic results? 
Overall the researchers found that between 2005 and 2015:
the numbers of people aged 16 to 24 who described themselves as non-drinkers rose from 18% to 29%
the numbers who had never drunk alcohol rose from 9% to 17%
the numbers who hadn't had a drink in the last week rose from 35% to 50%
the numbers who drank above recommended weekly limits fell from 43% to 28%
the numbers who had engaged in binge-drinking fell from 27% to 18%

The increase in non-drinking was seen in most subgroups, including both age groups and genders, north and south of the country, urban and rural areas, deprived and non-deprived areas, and those in and not in education or employment.

The numbers of non-drinkers rose among white young people but not among those from ethnic minorities. However, 68% of young people from ethnic minorities described themselves as non-drinkers in 2015, compared to 20% of white young people.

People with different health behaviours showed some difference in terms of drinking. Non-drinking increased among non-smokers but not among young people who smoked. It also increased among those who did high levels of physical activity, but not those who did less exercise.

This may suggest differences in health awareness, though non-drinking rates did increase in people with low fruit and vegetable consumption and regardless of BMI.

The researchers did not see an increase in non-drinking among people with lower scores of health and mental wellbeing.

How did the researchers interpret the results?
The researchers said their results "might suggest that the norms around non-drinking are changing, and this behaviour is becoming more mainstream among young people".

They said "increasing rates of non-drinking among young people are to be welcomed" and noted that the decline in drinking "may influence lower average consumption overall, which tends to reduce problematic drinking".

They said it is "difficult to pinpoint a single factor" behind the decline in drinking, but speculated it may be because of stricter licensing laws, increased awareness of the harms of alcohol, and changes in the way young people spend their leisure time – for example, using social media rather than meeting in a pub or bar.

Conclusion
We don't know for sure from this study why young people are increasingly turning away from drinking alcohol. However, the figures suggest a robust trend, which may or may not continue in future.

The decline in drinking could be due to increasing health awareness among young people and people making healthier lifestyle choices. From a public health point of view, this is probably good news, not least because the numbers of young people engaging in harmful binge drinking is also in decline.

The study has some limitations:
Some of the subgroups considered were quite small, which means the data for these groups may be less reliable. 

Although the participants were surveyed every year, not all of the health questions were asked each year. So in some years there's missing data for the amount of exercise people took, the amount of fruit and vegetables they ate, or for their mental health status. 

Cross-sectional surveys show only a snapshot or series of snapshots in time, so we don't know how the findings relate to changing habits among individuals over time.

Despite the drop in numbers of young people drinking, 28% of young people still reported drinking above recommended levels on at least 1 day in the week they were surveyed, in 2015. The lack of change in drinking habits among young people who smoked was also notable. There are still issues to address and people who may benefit from more support to reduce their alcohol intake.

Current UK guidelines advise men and women to drink no more than 14 units of alcohol a week; equivalent to 6 pints of average-strength beer or 10 small glasses of low-strength wine.

Find out about calculating units of alcohol.

https://www.nhs.uk/news/lifestyle-and-exercise/young-people-turning-their-backs-alcohol/

Analysis by Bazian
Edited by NHS Website

Thursday, October 4, 2018

Behind The Headlines - Cannabis has 'more lasting effect on teenage brains than alcohol'

Each day the NHS Choices team selects health stories that are making headlines. These, along with the scientific articles behind the stories, are sent to Bazian, a leading provider of evidence-based healthcare information. Bazian's clinicians and scientists analyse the research and produce impartial evidence-based assessments, which are edited and published by NHS Choices.

Cannabis has 'more lasting effect on teenage brains than alcohol'
Thursday October 4 2018
"Cannabis 'more harmful than alcohol' for teen brains," reports BBC News.

Canadian researchers investigated the links between alcohol and cannabis use and performance on various tests of brain function in 3,826 school pupils over 4 years, starting at age 12 to 13. They found teens who used cannabis performed less well, especially in tests of memory and impulse control.

The researchers said teenagers with worse memory and impulse control were more likely than other teens to use alcohol and cannabis. However, an increase in cannabis use in 1 year was associated with lower test scores that year and also in the following year, suggesting that cannabis could have a lasting effect on their brain function. The researchers did not find this result in teens using alcohol.

Cannabis also seemed to have greater effects in younger teens compared with older teens.

This study will add to the body of research assessing the potential cognitive and mental health effects of cannabis. As is often the case with such research, it's difficult to determine whether cannabis directly causes these effects or whether people at risk of cognitive or mental health problems may be more likely to use cannabis.

We do know that the brains of teenagers are still developing, so any drug or substance that can affect the brain, be it illegal or legal, could possibly have long-term effects.

There are also a number of health risks relating to cannabis use. Read more about how cannabis can lead to health problems.

Where did the story come from?
The researchers who carried out the study were from the University of Montreal, Centre Hospitalier Universitaire Sainte-Justine and Dalhousie University in Canada. It was funded by the Canadian Institutes of Health and published in the peer-reviewed journal The American Journal of Psychiatry.

The study was widely reported in the UK media. The media reports were broadly accurate but the headlines tended towards scaremongering. The Sun referred to cannabis as "brain rot" while the Mail Online implied the results lasted into adult life – which we do not know, as students were not followed up beyond age 16 to 17.

What kind of research was this?
The researchers carried out a cohort study using data from a previously-reported randomised controlled trial (RCT). The RCT aimed to assess the effect of a personality-targeted drugs and alcohol prevention programme. It assigned schools to deliver the programme to adolescents (average age 13) either immediately, or 3 years later (a delayed intervention condition).

Cohort studies are useful when investigating links between risk factors such as drug and alcohol use, and outcomes like poor brain functioning. However it remains a challenge to show that alcohol or drug use is a direct cause of poor brain function.

What did the research involve?
The trial recruited 3,826 school pupils in 7th grade (age 12 to 13). Pupils underwent computerised tests of brain function every year in school, and filled in a confidential online questionnaire about their cannabis and alcohol use. They continued in the study for 4 years.

The computerised brain function tests measured:
-working memory – the short-term memory that allows you to remember information sufficient to complete tasks
-perceptual reasoning – the ability to use information from our senses to understand the world around us
-delayed recall memory – the longer-term ability to remember something after a period of distraction
inhibitory control – the ability to control natural impulses, for example not to respond to a stimulus

For this study, the researchers compared the brain function scores to pupils' reported use of alcohol or cannabis. This showed whether pupils with poorer brain function in particular areas were more likely to use cannabis or alcohol, and vice versa. They then looked at how students performed year on year, and how that was linked to their reported alcohol or cannabis intake in that year, and in the previous year. This helped to show whether changes in pupils' substance use predicted changes in their test results.

Researchers took into account pupils' family income, gender, ethnicity and whether they lived with both biological parents.

What were the basic results?
The researchers reported results separately for cannabis and alcohol.

For cannabis, they said:
-pupils who used cannabis more frequently over 4 years had poorer results on working memory, -perceptual reasoning and inhibition control tests, compared to those who did not use cannabis
-pupils who increased how much cannabis they used had poorer results than expected in delayed memory tests in the same year
-pupils who increased their cannabis use had poorer results than expected in inhibition control the following year
-stronger links were observed in early adolescence compared with later adolescence

For alcohol:
-pupils who drank more alcohol more often over 4 years had poorer working memory, perceptual reasoning and inhibitory control
-pupils' changes in alcohol use over time did not seem to be related to their brain function tests

How did the researchers interpret the results?
The researchers said their results showed a "common vulnerability" to using cannabis and alcohol, among pupils with poorer working memory, perceptual reasoning and inhibition control.

The results also supported "a lasting, or neurotoxic, effect of cannabis" on inhibition control and working memory, meaning that the effects on the brain lasted beyond the period that the pupil was using cannabis.

Conclusion
This complex analysis suggests that cannabis use by teenagers may have an ongoing effect on their brain function, particularly in the areas of:
-working memory (important for completing tasks)
-perceptual reasoning (important for understanding the world)
-inhibition control (important for learning to resist harmful impulses)

The main difficulty is that we still don't know with certainty whether teens who used alcohol and cannabis had worse brain function because of substance use, or whether they were more likely to use alcohol and cannabis because of their poorer brain function.

Similarly we can't pull apart the influence of confounding health, lifestyle and environmental factors. We don't have a full picture of how other circumstances in their lives, such as peer groups or the home environment, might affect both drug and alcohol use and brain function and academic performance.

If cannabis is having a direct effect on brain function, we can't tell easily from this study is how big of an impact this might be. The differences in test results are not easily understood by non-experts. We don't know, for example, if the teenagers in the study who used cannabis were less likely to achieve educational or vocational qualifications, or to go on to academic or professional success.

An additional limitation to be aware of is that drug and alcohol use was self-reported. Although teenagers were told the questionnaire was confidential, some may have been reluctant to answer truthfully.

Overall the study adds to evidence that cannabis is not a risk-free drug, especially for teenagers and young people. So avoiding cannabis use during the teenage years – as with any time of life – seems to be a sensible precaution. This study gives teenagers another reason to think twice about using cannabis.

Analysis by Bazian
Edited by NHS Website 

Wednesday, September 26, 2018

Behind The Headlines: Older adults mixing prescription drugs and herbal remedies

What is Behind the Headlines?
Each day the NHS Choices team selects health stories that are making headlines. These, along with the scientific articles behind the stories, are sent to Bazian, a leading provider of evidence-based healthcare information. Bazian's clinicians and scientists analyse the research and produce impartial evidence-based assessments, which are edited and published by NHS Choices.

Concerns raised about older adults mixing prescription drugs and herbal remedies
Tuesday September 25 2018
"One million over-65s could be suffering dangerous side effects from mixing 'hazardous' combinations of drugs and herbal remedies, study warns," reports the Mail Online.

This follows a postal survey of 149 adults aged 65 and above from southeast England. The survey wanted to see whether people were choosing to take herbal or dietary supplements while also taking prescription medication. All respondents were taking at least 1 prescription drug, and a third of them were also taking some kind of supplement.

Most of the combinations were not harmful, but the researchers did find some people taking combinations that were potentially harmful.

These included:
a class of blood pressure drug (calcium channel blockers) with the herbal remedy St John's wort, which may reduce the effectiveness of the blood pressure drug
the type 2 diabetes drug metformin with glucosamine, which may affect blood glucose control
another blood pressure medication bisoprolol with omega-3 fish oil, which may further reduce blood pressure

The study gives an indication of how common supplement use is, and in some cases raises concerning patterns. However, it was a very small study and it is difficult to know whether the results would generalise to the wider population. There may be other drug-supplement interactions that were not found in this small group, but which might exist in other populations.

Some people mistakenly think a treatment or supplement marketed as "herbal" means it does not cause any side effects or drug interactions.

If you are unsure whether it is safe to take a supplement with your prescribed medication, read the leaflets provided with both medicines, or talk to your pharmacist or GP.

It's worth noting that these sorts of drug interactions can affect people of any age, not just people aged over 65.

Where did the story come from?
This study was carried out by researchers from the University of Hertfordshire and NHS Improvement. The study did not receive any funding. It was published in the peer-reviewed British Journal of General Practice.

The UK media generally covered the story fairly well, although the headlines tended to focus on the estimate that more than a million people could be affected. This figure is uncertain as it was based on a very simple calculation scaling up from a small study.

Also, many of the papers used the phrase "alternative medicines", when some of the substances studied in this research were actually commonly used food and vitamin supplements.

By talking about alternative medicines, people might not realise that this study is relevant to them, as they may have a different understanding of that phrase. 

What kind of research was this?
This was a cross-sectional survey, which means that a group of people were studied at a single point in time. This kind of study has the benefit of being relatively simple and quick to carry out. It's also a good way to look at how common something is (like use of herbal supplements) at a particular time.

However, cross-sectional studies can't tell us much more than this or explore the reasons behind observed patterns. We don't know the details of why people were taking drugs and supplements at the same time, for how long they had done this, and whether this had caused problems for them. Also, studies need to include a large and random cross-section of the relevant population to be able to give a reliable estimate of how common something is. So this small localised study may not be truly representative.

What did the research involve?
Between January and April 2016, this study mailed questionnaires to 400 older adults who were not living in care homes. Some were from a GP practice based in a rural area of Essex with a mainly white population. The others were from a GP practice in an area of London with a higher proportion of people from black, Asian and other minority ethnic groups.

Eligible participants were randomly selected people aged 65 or over who were taking at least 1 prescription medication. People with dementia, those who were terminally ill, and those who would not be able to consent to participate were excluded.

The questionnaire asked people what prescription drugs they were taking, as well as what "herbal medicinal products" or dietary supplements they might also be using. The questionnaire included examples of common herbal products (such as St John's wort or gingko) so that people understood what might be included in that category.

The researchers used a database to check whether people were taking any combination of prescription medicine and herbal remedy known to be potentially harmful. They labelled each interaction according to the following criteria:

action: whether it needed action or not
severity: how likely it was to cause a problem for the patient if the situation was not managed
evidence: how good is the evidence around the interaction

Reminder letters were sent after 2 weeks, and further questionnaires were then sent to people who hadn't previously responded. In total, 149 people responded and could be included in the analysis.

What were the basic results?
People were taking an average of 3 prescription drugs on a regular basis, with the most common including statins, beta-blockers and calcium channel blockers (used in the treatment of heart conditions and high blood pressure) and non-steroidal anti-inflammatory drugs (NSAIDs).

Around a third (33.6%) of the people in the study were using herbal remedies or supplements alongside their regular medications. This rate was higher in women (43.3%) than men (22.5%). People who were using herbal remedies or supplements were taking just 1 on average, though some people took as many as 8.

Most of the people (78%) who took supplements alongside their prescribed medication were taking vitamin and mineral supplements including cod liver oil, multivitamins, vitamin D and glucosamine.

They found 20% of people were using herbal products only. The most common were evening primrose oil, valerian, Nytol Herbal®, and garlic. Just over half of the reported potential interactions were considered to not be of clinical significance. However, 21 combinations were identified as having uncertain consequences, and 6 were considered potentially hazardous or significantly hazardous.

The combinations considered particularly risky were:
-the supplement Bonecal with levothyroxine (medicine for an underactive thyroid); the calcium in Bonecal reduces the effectiveness of levothyroxine
-peppermint taken with the medicine lansoprazole (which lowers stomach acid) – the medicine may affect the protective coating of peppermint capsules, which could lead to side effects caused by the peppermint
-St John's wort with the blood pressure drug amlodipine, which may make the drug less effective
-the supplement glucosamine with metformin (a diabetes drug), a combination that may affect blood glucose control 
-omega-3 fish oil with the blood pressure drug bisoprolol, which can lower blood pressure too much
the herbal remedy gingko with the stomach acid drug rabeprazole – this makes the drug less effective

How did the researchers interpret the results?
The researchers noted that if their study was representative of the population as a whole, then potentially 1.3 million older adults in the UK might be at risk of at least 1 herb-drug or supplement-drug interaction. They suggest GPs should routinely question the use of herbals and supplements among older adults.

Conclusion
This study gives us an interesting snapshot into the habits of a group of older adults who are using supplements alongside their prescription medications.

But we don't know how representative this study is of the wider population of older adults in the UK. The study includes patients from only 2 GP surgeries in southeast England. Although the researchers chose practices with different population characteristics, the people in the study might not be representative of the country as a whole.

The study was also very small, at just 149 people. We don't know anything about the people who did not participate. For example, it may be that these people were more likely to be users of herbal remedies and didn't want to share this information with their doctor. Or they might not have used herbal remedies at all and didn't think the study was relevant to them. Either way, this could affect the results and mean the study is not representative.

Finally, the study did not explore the reasons why people were taking supplements or herbal products alongside prescribed drugs, for how long they had done this, and whether they were aware of potential interactions. We also don't know whether there were any actual side effects or harms reported by the people in the study.

If you are unsure whether it is safe to take a herbal remedy or supplement along with your regular medication, talk to a pharmacist or your GP. It is also a good idea to do this if you are taking a lot of different medications that have been added to your prescription over the years, or if you are unsure what any of your medications are for.

Analysis by Bazian
Edited by NHS Website

Links to the headlines 
Mail Online, September 25 2018

Alternative medicine use may put 1.3 million older people at risk, study suggests
The Independent, September 25 2018

Millions of pensioners ‘at risk’ from alternative remedies as they ‘could react with their prescription drugs’
The Sun, September 25 2018 

The Times (subscription required), September 25 2018

Links to the science
Agbabiaka TB, Spencer NH, Khanom S, Goodman C. Prevalence of drug–herb and drug–supplement interactions in older adults: a cross-sectional surveyBritish Journal of General Practice. Published online September 24 2018

Saturday, April 14, 2018

Behind the Headlines - People who drink above UK alcohol guidelines 'lose one to two years of life'

What is Behind the Headlines?
Each day the NHS Choices team selects health stories that are making headlines. These, along with the scientific articles behind the stories, are sent to Bazian, a leading provider of evidence-based healthcare information. Bazian's clinicians and scientists analyse the research and produce impartial evidence-based assessments, which are edited and published by NHS Choices.

People who drink above UK alcohol guidelines 'lose one to two years of life'
Friday April 13 2018
"Just one alcoholic drink a day could shorten your life," reports BBC News.

A huge study of almost 600,000 drinkers showed that people who drank more than 12.5 units (100g) of alcohol a week were likely to die sooner than those who drank no more than this amount. The results applied equally to women and men.

The current UK guidelines advise limiting alcohol intake to 14 units a week for women and men. This is equivalent to drinking no more than 6 pints of average-strength beer (4% ABV) or 7 medium-sized glasses of wine (175ml, 12% ABV) a week.

These limits are lower than the levels for many other countries, but this latest study suggests they are about right.

The researchers calculated life would be shortened by an average of 1.3 years for women and 1.6 years for men for people aged 40 who drank above the UK weekly limit in comparison with those drinking below the limit.

The study also looked at the likelihood of having a range of non-fatal, but potentially life-changing, cardiovascular conditions, including heart attacks, heart failure and stroke.

Drinking more alcohol was linked to higher chances of all cardiovascular conditions except heart attacks, where it was linked to a lower chance. However, greater risks from other causes of death outweighed any advantage that might bring.

This high-quality study provides further evidence to support the current UK guidelines advising people to drink no more than 14 units a week. Find out more about calculating units of alcohol.

Where did the story come from?
The study was carried out by a collaboration of 120 researchers worldwide, from regions including Australia, Europe, Japan, the UK and the US. It was funded by the UK Medical Research Council, British Heart Foundation, National Institute for Health Research in the UK, European Union and European Research Council.

It was published in the peer-reviewed medical journal The Lancet on an open-access basis so is free to read online.

The study was covered widely in the UK media, with many outlets reporting variations on the life expectancy that could be lost for every drink or number of drinks consumed.

The Daily Telegraph wrote: "Six glasses of wine a week is too much despite government guidelines suggesting it is a safe limit." While the study did suggest 12.5 units is the threshold above which risks start to rise, the difference in risk between people drinking 12.5 and 14 units was small. There's also no agreed classification for the size of a glass of wine.

As statistics expert Professor David Spiegelhalter explained, the study "estimates that, compared to those who only drink a little, people who drink at the current UK guidelines suffer no overall harm in terms of death rates".

What kind of research was this? 
This was a meta-analysis of individual-level data from 83 prospective cohort studies carried out in 19 countries. This type of research – especially when carried out at this scale and with the care the authors took to ensure their methods were robust – is a good way to summarise the best research we have on a particular subject.

However, the studies analysed were all observational studies, as it wouldn't be ethical to carry out studies where some people were encouraged to drink an unhealthy amount of alcohol. This means we have to be cautious when saying alcohol was the direct cause of the additional deaths, because other confounding factors may have affected the results.

What did the research involve? 
Researchers gathered data from 83 studies, starting between 1964 and 2010, that had information about drinkers who didn't have cardiovascular disease at the start of the study, their level of alcohol consumption and additional health data, and that followed up the participants.

After making adjustments for potential factors that might affect the results – such as age, sex, smoking and physical exercise – they carried out statistical analyses to calculate how different levels of alcohol consumption affected people's risk of:
developing cardiovascular disease
death from any cause

The researchers used a big dataset of life expectancy models to calculate how the relative risks of drinking different amounts of alcohol would affect the life expectancy of people aged 40.

What were the basic results?
Of the 599,912 people in the study, 40,310 died and 39,018 got cardiovascular disease during an average 7.5 years of follow-up. About half of the people in the study reported drinking more than 12.5 units of alcohol a week.

Looking at different levels of alcohol consumption, the researchers found:
people drinking up to 12.5 units of alcohol a week had the lowest risk of death from any cause

above that level, the risk of death rose to a more than 30% increased risk for those drinking more than 37 units a week

each additional 12.5 units of alcohol consumed each week increased the risk of stroke by 14% (hazard ratio [HR] 1.14, 95% confidence interval [CI] 1.10 to 1.17)

each additional 12.5 units of alcohol consumed each week decreased the risk of heart attack by 6% (HR 0.94, 95% CI 0.91 to 0.97)

the risk of all other cardiovascular conditions increased with each additional 12.5 units of alcohol consumed

When they applied their figures to life expectancy at age 40, the researchers calculated that compared with people drinking up to 12.5 units a week:
those who drank 12.5 to 25 units a week were likely to live 6 months less
those who drank 25 to 44 units were likely to live 1 to 2 years less
those who drank more than 44 units were likely to live 4 to 5 years less

Looking at UK limits (14 units a week), the researchers said that compared with those who drank within current limits:
men who drank above the limits would lose an average of 1.6 years (95% CI 1.3 to 1.8)
women who drank above the limit would lose an average of 1.3 years (95% CI 1.1 to 1.5)

How did the researchers interpret the results? 
The researchers said their main finding was that the lowest risk for avoiding harm from alcohol was found in people drinking no more than 100g, or 12.5 units, of alcohol a week.

They said their detailed analysis of cardiovascular conditions helped to explain the complex links between drinking alcohol and cardiovascular disease, which increased risk of conditions mainly caused by high blood pressure but slightly decreased risks of heart attacks – possibly because of links between alcohol and cholesterol.

They concluded: "These data support adoption of lower limits of alcohol consumption than are recommended in most current guidelines."

Conclusion
This was an impressive study that analysed a lot of high-quality data. It offers strong evidence to support recommendations that people drink within relatively low alcohol limits, like those recently introduced in the UK.

The work regarding cardiovascular disease and heart attacks is useful and challenges the widespread belief that alcohol reduces the risk of cardiovascular conditions. While that may be true for heart attacks, it's isn't for stroke or other conditions.

The study did have a couple of limitations that are worth noting.

In many of the individual studies included in the meta-analysis, the participants were asked only once about how much alcohol they drank – and people are notoriously bad at accurately reporting their drinking. However, if people in the studies routinely underestimated their alcohol consumption, that would mean the meta-analysis results tend towards underestimating the harm alcohol causes.

And while the researchers did their best to account for a range of factors that could have affected the results, it's always hard to control for those completely.

Overall, the study adds weight to the recommendations that both women and men drink within the UK limits of 14 units of alcohol a week.

Analysis by Bazian
Edited by NHS Choices

Links to the headlines 

Thursday, March 1, 2018

Behind the Headlines: High-strength skunk 'now dominates' UK cannabis market

High-strength skunk 'now dominates' UK cannabis market

"Almost all cannabis seized by police now comprises high-strength varieties, with outdoor-grown herbal strains and hashish barely found," The Guardian reports. The news is based on researchers analysing samples of cannabis seized by 5 police forces in 2015 and 2016.

They found almost all the cannabis (93.6%) was sinsemilla, also known as skunk. This is a potent form of herbal cannabis often grown in the UK in indoor "cannabis farms" which has been specifically bred to have high levels of tetrahydrocannabinol (THC).

THC is the psychoactive chemical in cannabis responsible for many of the pleasurable effects people get when using the drug. THC has also been linked to an increased risk of developing mental health problems, such as psychosis (where a person is unable to tell the difference between reality and their imagination).

Analysis of samples of the drugs showed a wide variation in the levels of THC, with an average level of 14.2% in sinsemilla, compared to 6.3% in resin.

Cannabis resin, which dominated the UK market before 2000, only accounted for 5.8% of the cannabis seized by police. Resin THC levels were higher than those recorded in a similar study in 2005.

Cannabis resin usually contains cannabidiol (CBD), a substance thought to protect against some of the dangerous effects of THC. Sinsemilla does not usually contain CBD.

This matters, because doctors think people who use cannabis with high levels of THC, especially without CBD to counteract it, are more likely to become addicted and develop mental health problems.

Where did the story come from?

The study was carried out by researchers from GW Pharmaceuticals, which produces a range of medical cannabinoid medicines, and from King’s College London. GW Pharmaceuticals could be seen to have a conflict of interest in highlighting the dangers of illegal cannabis, as it is currently researching a range of medical treatments based on cannabidiol (CBD).

One of the researchers was funded by the Medical Research Council. The study was published in the peer-reviewed journal Drug Test Analysis.

The study was widely covered in the UK media. Some of the headlines – such as the Mail Online's "Terrifying rise of super-strength 'skunk' cannabis" - ramp up the fear, but by and large the study was accurately reported.

What kind of research was this? 
This was a laboratory analysis of samples of drugs seized by police. The study gives a snapshot of the types of cannabis and range of potency of cannabis being sold illegally. However, we don't know how representative the samples are of the types of cannabis being used in the UK, as police may not target all potential cannabis users equally.

What did the research involve? 
Researchers contacted 5 police forces which had been involved in previous surveys of cannabis, in 2005 and 2008. The forces were asked to send all seized cannabis samples in their property stores for analysis.

The researchers sorted the cannabis by type, then selected a representative sample to analyse for levels of THC, CBD, and a degraded form of cannabinoid, CBN, which is less potent and is a result of THC breaking down.

Cannabis came from Kent and London Metropolitan districts (in 2015) and Derbyshire, Merseyside and Sussex (in 2016). It was sorted into 3 types:
resin
sinsemilla
natural herbal cannabis (a less-potent type of cannabis, often imported from Morocco)

Researchers analysed about half of the samples of sinsemilla, and all of the samples of resin and natural herbal cannabis, as there were fewer of them. They analysed 250mg from each sample, which they say is a typical amount of cannabis used in 1 joint.

To see whether the time the sample had been held by the police affected the strength, they measured 34 samples where the length of storage was known, and looked at whether CBN levels were linked to time stored.

What were the basic results? 

The vast majority of the 995 cannabis samples were sinsemilla:
929 (93.6%) of these were sinsemilla, compared to 708 (84.5%) in 2008 and 247 (50.6%) in 2005
58 (5.8%) were resin, compared to 104 (14.2)% in 2008 and 169 (42.7%) in 2005
6 (0.6%) were traditional herbal cannabis, compared to 14 (1.3%) in 2008 and 39 (6.7%) in 2005

The average THC content of sinsemilla samples was 14.2%, similar to the 13.9% found in 2005. However, the range varied from 1.9% to 22.5%, with most being around 10% to 20%.

Average THC content of resin was much lower, at 6.3%, although this varied from no discernible THC to 29% in 1 sample found in a prison. The average strength was much higher than in 2005, when average THC concentration was 3.7%.

Only 1 of the sinsemilla samples contained CBD, the protective agent. While most resin samples did contain CBD, researchers found the average level had dropped from 4.3% in 2005 to 2.3% in 2015/6.

The analysis found no indication that length of time in police storage affected the strength of cannabis.

How did the researchers interpret the results? 
The researchers said: "This trend presents an increased risk of harm to those susceptible to the development of psychotic disorders following cannabis use." They suggest the need for a nationwide survey.

Conclusion 

Cannabis has often been dismissed as a relatively harmless street drug, compared to class A drugs such as cocaine and heroin. However, mounting evidence suggests it may have a harmful effect on mental health, particularly for teenagers and adolescents, increasing the chances of problems including panic attacks, anxiety and psychosis.

Although research is still taking place, it seems that stronger sinsemilla cannabis (aka skunk, which contains more THC and little CBD), raises the risk of mental health problems and addiction, compared to cannabis resin, which tends to have less THC and more CBD.

It's concerning that this study suggests sinsemilla is becoming much more common, and that where resin is on sale, it has more THC and less CBD than a decade ago. People who base their ideas about cannabis on the drug they smoked many years ago may not realise the strength and potential harm of the cannabis sold on the street today.

However, the study has some limitations:
It only looked at drugs seized by police. It's possible that police may prioritise arresting and confiscating drugs from people selling sinsemilla, because of its perceived harm. This might mean the proportion of cannabis resin in the study could be artificially low.

It only analysed a proportion of the samples of sinsemilla, and only 250mg from each sample. The overall sample strength might have varied, because the cannabis plant's concentration of THC varies in different parts.

Only 5 police forces were involved, so we don't know if the results would apply equally around the country.

Cannabis doesn't just affect mental health, smoking any form of cannabis can be bad for your health in other ways.

It can also:
damage your lungs
increase your risk of road accidents
damage your fertility and, if smoked when pregnant, damage the unborn baby

Find out more about the effects of cannabis.

Analysis by Bazian
Edited by NHS Choices

Links to the headlines 
Drug Testing and Analysis

Saturday, December 2, 2017

Behind the Headlines - Some type 1 diabetes cases in adults misdiagnosed as type 2

What is Behind the Headlines?
Each day the NHS Choices team selects health stories that are making headlines. These, along with the scientific articles behind the stories, are sent to Bazian, a leading provider of evidence-based healthcare information. Bazian's clinicians and scientists analyse the research and produce impartial evidence-based assessments, which are edited and published by NHS Choices. The following article was published December 1, 2017; analysis by Bazian and edited by NHS Choices.

Some type 1 diabetes cases in adults misdiagnosed as type 2 
Friday December 1 2017

“Doctors 'wrong to assume type 1 diabetes is childhood illness',” says The Guardian.

This follows a study looking at a large number of adults in the UK to see if they had diabetes and if so, which type of the condition they had.

Type 1 diabetes is an autoimmune condition where the body destroys the insulin-producing cells of the pancreas, so is reliant on life-long insulin injections. Type 2 diabetes is a condition where the person produces limited insulin, or their body can't use it so well. It can be managed in the early stages with changes to diet and medication.

Type 1 diabetes is often thought of as a “childhood illness” as most people are diagnosed at a young age. For this reason, people who develop diabetes as adults are often assumed to have type 2. Perhaps the most famous example is Prime Minister Theresa May who was, at first, misdiagnosed with type 2 diabetes in 2013, when in fact further tests revealed she had type 1.

This study looked at 13,250 people diagnosed with diabetes at a range of ages. Of all people who developed type 1 diabetes, surprisingly 42% were not diagnosed until after the age of 30.

However, only 4% of all newly diagnosed diabetes in the over 30s were type 1. Therefore, although type 1 diabetes starting in adulthood is uncommon, it still highlights the need for healthcare professionals to be aware that not all people who develop diabetes in adulthood automatically have type 2.

Making sure that people receive the correct diagnosis, and therefore the correct treatment, is crucial.

If you have been diagnosed with type 2 diabetes but are not responding to treatment, it may be worth discussing the possibility of further testing with your doctor.

Where did the story come from?
The study was carried out by researchers from the University of Exeter using data from a nationwide study called UK Biobank. It was funded by The Wellcome Trust and Diabetes UK. It was published in the peer-reviewed medical journal The Lancet: Diabetes and Endocrinology.

The story was covered by the BBC and The Guardian, both of which accurately covered the key findings and explained the importance of receiving a correct diagnosis to ensure people are given the right treatments.

What kind of research was this? 
This researchers used data from a large, ongoing cohort study called UK Biobank which started in 2006. The study aimed to see how people with genes predisposing them to type 1 diabetes developed the condition in later life rather than in childhood or teenage years as usual.

UK Biobank involves more than half a million adults across the country, and has followed them up for a number of years. As well as attending health screening sessions, participants have also given blood samples from which genetic information can be recorded. For this research, a snapshot was taken of people from UK Biobank who were of white European descent, and who had genetic data available.

A cohort study that followed people from childhood throughout their lives may have been able to look at this in more detail. But the size and coverage of the UK Biobank study make this a useful starting point to look at whether people with genetic risk factors for type 1 diabetes are diagnosed in adulthood or childhood.

What did the research involve? 
The study involved a sample of 379,511 people from the UK Biobank study, of whom a subgroup had diabetes. All were of white European background and had genetic data available. None of the people were related to each other.

The researchers assessed all people for genetic variants known to be associated with type 1 diabetes. They then gave each person a genetic risk score for their risk of developing type 1 diabetes.

Self-reports of a diabetes diagnosis were assessed by questionnaire at study enrolment or later follow-up. People provided information about the age they received a diagnosis, and whether they used insulin within one year of diagnosis (reliance on insulin would indicate type 1). They also reported any hospital admissions for diabetic ketoacidosis (a serious complication of diabetes), and general health such as body mass index.

For the analysis, the researchers compared people with ‘high risk’ or ‘low risk’ for type 1 diabetes based on the results of the risk score. They limited analysis to cases of type 1 or type 2 diabetes occurring in people aged 60 or under at time of diagnosis, as after that point any new cases are almost certain to be type 2 diabetes.

What were the basic results? 
In the study sample there were 13,250 people with diabetes, 55% of whom had high genetic risk scores and the remainder had low risk scores.

There were 1,286 cases (9.7%) of type 1 diabetes, and all of these occurred in people with the high risk score:
18% of those with a high risk score were diagnosed with type 1 diabetes, the remainder with type 2
42% of those in the high risk group diagnosed with type 1 (537) were diagnosed between the ages of 31 and 60, with the remainder diagnosed under the age of 30 (as is more usual)
of all people aged under 30 at time of diabetes diagnosis (all risk categories), 74% had type 1 diabetes
of all people aged 31 to 60 at time of diabetes diagnosis, 4% had type 1 diabetes
across all ages of life, people with a high genetic risk score were more likely to be diagnosed with any type of diabetes than people with a low risk score

All people diagnosed with type 1 after the age of 30 needed insulin treatment, compared to only 16% of people diagnosed with type 2 (who started insulin later, after 7 years on average). They also had a lower body mass index (BMI) than those with type 2.

How did the researchers interpret the results?
The researchers stated their findings have “clear clinical implications”, alerting healthcare professionals to the fact that type 1 diabetes can occur in the over-30s. They recommend that recognition of late-onset type 1 diabetes is an important area of improvement for both medicine and research.

Conclusion 
This study gives us an important insight into the way in which type 1 diabetes has been mislabelled as a “childhood condition”. It suggests that a number of people with genetic risk factors are also diagnosed in midlife, when most new diabetes diagnoses would be thought to be type 2.

However, there are a few points to note:
The study shows that of all people diagnosed with diabetes after age 30, the vast majority (96%) were still type 2 diagnoses. Therefore, though practitioners need to be aware, this only accounts for a small proportion of all diagnoses.

Even among people with hereditary risk factors for type 1 diabetes, most diagnoses were still type 2.
The diagnosis of diabetes was based on people's own reports, rather than looking at medical records.

People are unlikely to be wrong about whether they have the condition or not, but there may be some uncertainty as to whether they self-reported the correct type, age at which they were diagnosed, or when they started insulin.

The study only looked at people from a white European background. Type 1 and type 2 diabetes prevalence and risk factors may differ in people from other ethnic backgrounds, so this study’s results cannot be generalised to everyone.

When the UK Biobank study started in 2006, the majority of people taking part were aged 40 or over. This means that they were children in the 1980s or earlier. Since that time, the diagnosis of diabetes may have improved. It would also mean that people who suffered complications from the disease and died in earlier life would not have been included.

The study can't tell us how many of these people with type 1 in later life may have been misdiagnosed initially, or had insulin treatment delayed when they needed this to start with.

People who commit to take part in studies like UK Biobank might be more active about monitoring and managing their health than people in the general population. Therefore people in this study may have had slightly different experiences when getting diagnoses, or have different lifestyle behaviours that could affect their risk of conditions like diabetes.

Nonetheless, this study highlights the fact that type 1 diabetes can begin in adulthood as well as in childhood. Adults diagnosed with diabetes must receive the correct diagnosis to get the right treatment as soon as possible. If you are concerned that you may have been misdiagnosed, ask the doctor in charge of your care for advice.

Link
https://www.nhs.uk/news/diabetes/some-type-1-diabetes-cases-adults-misdiagnosed-type-2/

Thursday, September 28, 2017

Behind The Headlines - Rates of newly diagnosed HIV increasing in over-50s

What is Behind the Headlines?
Each day the NHS Choices team selects health stories that are making headlines. These, along with the scientific articles behind the stories, are sent to Bazian, a leading provider of evidence-based healthcare information. Bazian's clinicians and scientists analyse the research and produce impartial evidence-based assessments, which are edited and published by NHS Choices.

Rates of newly diagnosed HIV increasing in over-50s
Wednesday September 27 2017

"HIV rises among over-50s as they neglect safe sex" is the headline from The Times.

The news is based on a European study that found more over-50s are being diagnosed with HIV compared with 12 years ago.

The study collected data on more than 360,000 people who had been newly diagnosed with HIV between 2004 and 2015 in Europe.

The researchers looked at infection rates over time according to age, route of transmission and country.

They found a number of differences between the patterns of infection and diagnosis in those aged 15 to 49 and in those aged 50 and over.

In the over-50s age group, though people remained more likely to become infected with HIV through heterosexual sex, the rate of infection in men who have sex with men and through drug injection had increased between 2004 and 2015.

But in younger adults, infection rates hadn't changed over time and men having sex with men remains the most likely route of transmission.

Older people were also more likely to be diagnosed when the disease was advanced compared with younger people.

This study highlights the need for people of all ages to be aware of the risks of HIV infection from unprotected sex.

HIV tests are free on the NHS and can be done in various places, including walk-in sexual health clinics. There are also home testing kits available.

Find out more about HIV tests and find HIV testing services near you.

Where did the story come from?
The study was carried out by researchers from the European Centre for Disease Prevention and Control in Sweden in collaboration with members of the European Union/European Economic Area HIV Surveillance Network.
It was funded by the European Centre for Disease Prevention and Control.
The study was published in the peer-reviewed journal The Lancet. The abstract is available free online.

Some of the media stories suggested the rise in HIV cases among older people was because this age group neglected messages about safer sex.

Mail Online went as far as saying: "Reckless sexual behaviour by divorcees is behind an increase in HIV cases among the over-50s, a major study suggests".

But the study didn't report on marital or relationship status, and didn't investigate sexual behaviour.
Several stories also focused on the number of older people who have been infected through heterosexual contact.

While heterosexual sex is the most likely transmission route for the over-50s age group, these rates have remained stable over the last 12 years.

It's the rate of infection from sex between men and from drug injection that has increased over time for this age group.

What kind of research was this?
This was an observational study using data sent by EU and EEC member states to the European Surveillance System for HIV.
This type of study is useful for identifying trends in diagnosis rates, but relies on accurate data reporting and collection.
Actual rates of HIV may be higher, as this only takes into account people who have had a positive test.

What did the research involve?
The researchers collated data from 31 countries on new cases of HIV diagnosed between January 2004 and December 2015.
The data was anonymised, but included:
  • date of diagnosis
  • age
  • sexual history
  • mode of transmission
  • country of birth
  • country of diagnosis
  • stage of disease according to CD4 count, with late diagnosis defined as less than 350 cells/µL and advanced disease as less than 200 cells/µL
They analysed the data according to two age groups: younger people aged 15 to 49 and older people aged 50 or over.

What were the basic results?
Overall, between 2004 and 2015:
  • There were 312,501 new cases of HIV in people aged 15 to 49, a rate of 11.4 per 100,000 people. This rate of infection didn't change over time.
  • There were 54,102 new cases of HIV in adults over 50, a rate of 2.6 per 100,000 people. The rate of infection increased by 2.1% per year over the 12-year period.
In the UK:
  • There was an increase of 3.6% in new diagnosis rates for older people between 2004 and 2015, from 3.1 to 4.32 new cases per 100,000 people. This is higher than the European average.
  • There was a 4% reduction in new diagnosis rates for younger adults during this time.
Diagnosis by age group:
  • Older people were more likely to have a delayed diagnosis, with significantly lower CD4 counts than younger adults.
Men compared with women:
  • Over the 12-year period, the average diagnosis rate for older men increased from 3.5 to 4.8 per 100,000, while older women had an increase from 1.0 to 1.2 per 100,000.
  • Over the same period, the average rate of diagnosis increased by 1.4% in younger men and reduced by 4.8% for younger women.
Mode of transmission in 2015:
  • The most common route of infection for older adults was heterosexual contact (42.4% of cases), followed by sex between men (30.3%), "other" or unknown causes (24.6%), and injecting drugs (2.6%).
  • For younger adults, sex between men was the most common route of infection (45.1% of cases), followed by heterosexual contact (30.8%), other or unknown (19.5%), and injecting drugs (4.6%).
Changes in mode of transmission from 2004 to 2015:
  • The rate of HIV infection from heterosexual sex remained stable in older people, and decreased in younger people.
  • Infection resulting from injecting drugs increased in older people and decreased in younger people.
  • The rates of HIV infection in men who have sex with men increased in both age groups, but more so in older people at 5.8% compared with 2.3%.
How did the researchers interpret the results?The researchers concluded that the "increasing new HIV diagnoses among older adults point towards the compelling need to heighten awareness among healthcare providers and deliver more targeted prevention interventions for this age group and the total adult population".

They were also careful to say that "no data for the reasons behind such an increase [in new HIV diagnoses in older people] have been published".

Conclusion
This was a well-conducted study and the results are likely to be reliable, though there are some limitations, including missing data.

For example, the researchers had no information on the migration status or CD4 count (an indicator for stage of the disease) for a quarter of cases.

This study found that although the overall rate of infection is higher in younger people, this has remained stable over the last 12 years while the rate of infection in older people has increased.
Some of the media stories focused on the finding that older people are most likely to have become infected through heterosexual sex.

While true, this is nothing new: the rate of infection from heterosexual sex has in fact been stable for over-50s over the study period, whereas the rates of infection in men having sex with men and drug use have both increased for this age group.

What makes further analysis of this trend difficult to interpret is the high proportion of people for whom "other" or "unknown" infection was recorded.

The finding that older people were more likely to have a delayed diagnosis highlights the importance of HIV testing for people of all ages who are at risk of infection.

What's of most concern is that the rates of infection remain high in all age groups despite public health campaigns about practising safe sex.

HIV tests are free on the NHS and can be done in various places, including walk-in sexual health clinics. There are also home testing kits available.

Find out more about HIV tests and find HIV testing services near you.
Analysis by Bazian
Edited by NHS Choices

Wednesday, July 5, 2017

Behind The Headlines - Heartburn drugs linked to premature death

Behind The Headlines: Analysis by Bazian edited by NHS Choices

What is Behind the Headlines?
Each day the NHS Choices team selects health stories that are making headlines. These, along with the scientific articles behind the stories, are sent to Bazian, a leading provider of evidence-based healthcare information. Bazian's clinicians and scientists analyse the research and produce impartial evidence-based assessments, which are edited and published by NHS Choices.

Heartburn drugs linked to premature death
"Millions of people taking common heartburn and indigestion medications could be at an increased risk of death," The Guardian reports after a US study found people taking proton pump inhibitors (PPIs) had a slightly higher risk of death than the control group.

PPIs reduce the amount of acid in the stomach. As well as being used to treat heartburn, they're often given to people as a protective measure if they're thought to be at risk of a stomach ulcer – for example, people who take daily low-dose aspirin, which is known to irritate the lining of the stomach.

This headline is based on research in 350,000 predominantly male US veterans who were prescribed PPIs or H2 blocker drugs to either treat heartburn or protect the stomach. PPIs and H2 blockers both work by reducing stomach acid.

The researchers found people who took PPIs had a greater risk of death from any cause compared with those who took H2 blockers or nothing at all.

But there was no proof that the increased risk of death was directly caused by the PPI drugs. The researchers tried to adjust for underlying health factors, such as cardiovascular disease, which is often treated with daily aspirin, but it's possible the effects of these or other factors could still have influenced the results.

If you've been prescribed PPIs, you shouldn't stop taking them without first consulting your GP. The risk of not taking them (such as a stomach bleed) may be greater than any risk associated with taking them.

Where did the story come from?
The study was carried out by researchers from VA Saint Louis Health Care System, Washington University School of Medicine, and Saint Louis University in the US.

No information on funding was provided, but the data the researchers analysed came from the US Department of Veterans Affairs.

The study was published in the peer-reviewed journal BMJ Open and is open access, so it's free to read on the BMJ website.

The UK media's coverage of the story was generally accurate, but the headlines failed to reflect the inherent limitations of the study – including the fact that the conditions people were taking PPIs for in the first place may also have been one of the main causes of death.

What kind of research was this?
This large cohort study of US veterans aimed to look at whether PPIs or H2 blockers were associated with risk of death.

H2 blockers are drugs like ranitidine (Zantac) that reduce stomach acid, and are commonly used to treat acid reflux or heartburn.

PPIs such as omeprazole work in a slightly different way, but are also used to protect the stomach, often in people who have ulcers or those at risk because they take anti-inflammatories or aspirin long term.

Both types of drugs are available on prescription, and some can be purchased over the counter in pharmacies.

As this was a cohort study, it can't prove that taking one drug directly causes death – it can only show there's an association. It might be the case that other health, sociodemographic or lifestyle factors, such as high body mass index (BMI), contributed to the higher risk of death.

randomised controlled trial (RCT) would give more reliable evidence on the direct effect of either taking the different drugs or doing nothing (control group) while controlling for other factors.
But RCTs can be expensive and time consuming to carry out. Cohort studies can be useful to assess potential adverse effects, as they're able to follow an extensive number of people (in this case 349,312) over a long period of time.

What did the research involve?
Researchers used the US Department of Veterans Affairs national databases to identify 349,312 people (average age 61, 94% male) who'd been prescribed acid suppression therapy (PPIs or H2 blockers) between 2006 and 2008. They looked at their likelihood of death by any cause over 5.71 years on average.

Information on deaths is routinely gathered by the Veterans Benefit Administration for all US veterans.

The 275,977 participants whose first acid reflux drug was a PPI were placed in the PPI group, while the 73,335 participants who received H2 blockers first were the reference group.
In the H2 blocker group, 33,136 participants were later prescribed a PPI and were placed in the PPI group from the point they started taking PPI drugs.

The main outcome of interest was drug use in relation to death.  The researchers also looked at how long the drugs were prescribed for.

They adjusted their data to take into account a number of things that could have influenced the results, including:
  • age
  • race
  • gender
  • kidney function
  • number of hospitalisations
They also took into account a range of chronic illnesses, including:
  • diabetes
  • hypertension
  • cardiovascular disease
  • peripheral artery disease
  • stroke
  • chronic lung disease
  • hepatitis C
  • HIV
  • dementia
  • cancer
  • a range of gastrointestinal illnesses

What were the basic results?
Overall, 23.3% of the entire cohort died over the 5.71-year follow-up. The rate was 12.3% in those using H2 blockers at the start of the study, 24.4% in those using PPIs at the start of the study, and 23.4% in those who'd ever used PPIs.
The researchers found:
  • PPI use was associated with increased risk of death compared with H2 blocker use (hazard ratio [HR] 1.25, 95% confidence interval [CI] 1.23 to 1.28)
  • PPI use versus no known exposure to acid suppression therapy (PPIs or H2 blockers) was also linked with a similar increased risk of death (HR 1.23, 95% CI 1.22 to 1.24)
Risks were similar when only looking at participants with no known gastrointestinal problems:
  • PPI versus H2 blocker use (HR 1.24, 95% CI 1.21 to 1.27)
  • PPI versus no known acid suppression therapy (HR 1.22, 95% CI 1.21 to 1.23)
Compared with participants taking PPIs for 30 days or less, risk of death gradually increased with the length of time they were taking them:
  • 31-90 days (HR 1.05, 95% CI 1.02 to 1.08)
  • 91-180 days (HR 1.17, 95% CI 1.13 to 1.20)
  • 181-360 days (HR 1.31, 95% CI 1.29 to 1.34)
  • 361-720 days (HR 1.51, 95% CI 1.47 to 1.56)

How did the researchers interpret the results?
The researchers concluded that, "The results suggest excess risk of death among PPI users; risk is also increased among those without gastrointestinal conditions and with prolonged duration of use. Limiting PPI use and duration to instances where it is medically indicated may be warranted."

Conclusion
This larger set of observational data finds that PPI drugs are associated with an increase in the risk of early death compared with either H2 blockers or no acid suppression drugs. This was the case for participants both with and without gastrointestinal problems.
It also appears as though the longer the PPIs drugs are taken, the greater the risk of death.
Considering that these drugs are widely used in the UK, these findings may cause concern. But the research has a number of important limitations:
  • The study was conducted in a population of mostly white, older US male veterans, which might limit the ability to generalise the results to the whole UK population.
  • Deaths can't be linked directly to the use of PPIs. The researchers have tried to adjust for many health and other characteristics that could be linked with both PPI use and higher risk of death, such as cardiovascular diseases, but we still can't be certain the influence of the disease has been fully taken into account.
  • Many of the deaths occurred in the first year, so could well be linked to underlying causes. There was also no information on cause of death.
  • The follow-up period only lasted around five years. Longer term death outcomes weren't examined – it may be that PPIs are associated with better outcomes for participants in the long term, but we can't say for sure either way.
  • The length of follow-up in the PPI group was more than two years longer than in the H2 blocker group, so it's unsurprising there was a greater risk of death given the extra two years of data collection.
  • The drugs were all prescribed in outpatient settings. Some brands of these drugs are available over the counter in the UK. There might be a difference between the groups of people who have their drugs prescribed and those who buy them over the counter, both in terms of risk and in the dose of the drugs.
  • This study can't attribute risk to any individual PPI drug. If there is a direct mortality risk from PPIs, it may differ according to which drug it is – but this study isn't able to tell us this.
Overall, this large study of good-quality data raises a clear link that needs further examination.
But people who have been prescribed PPIs shouldn't stop taking them – the risk of not doing so may be much greater than any risk the drugs pose. For example, a bleeding stomach ulcer can be very serious and potentially life threatening.
If you're concerned about your medication, you should discuss your treatment options with your GP or the doctor in charge of your care.

Analysis by Bazian
Edited by NHS Choices
The Independent, July 4 2017

Links to the science
Xie Y, Bowe B, Li T, et al. Risk of death among users of Proton Pump Inhibitors: a longitudinal observational cohort study of United States veterans. BMJ Open. Published online July 4 2017

Saturday, July 23, 2016

Behind the Headlines - Alcohol 'a direct cause of seven types of cancer'

Behind The Headlines: Analysis by Bazian edited by NHS Choices

What is Behind the Headlines?
Each day the NHS Choices team selects health stories that are making headlines. These, along with the scientific articles behind the stories, are sent to Bazian, a leading provider of evidence-based healthcare information. Bazian's clinicians and scientists analyse the research and produce impartial evidence-based assessments, which are edited and published by NHS Choices.

Alcohol 'a direct cause of seven types of cancer'
Friday July 22 2016
Several studies looking at whether alcohol causes cancer were looked at during the research

Alcohol can increase your cancer risk
"Even one glass of wine a day raises the risk of cancer: Alarming study reveals booze is linked to at least seven forms of the disease," reports the Mail Online.

The news comes from a review that aimed to summarise data from a range of previous studies to evaluate the strength of evidence that alcohol causes cancer.

The main finding was that existing evidence supports the link between alcohol consumption and cancer at seven sites, including the throat, gullet, liver, colon, rectum and female breast.

The links were said to be strongest for heavy drinking, but this study suggested that even low or moderate drinking may contribute to a significant proportion of cancer cases because of how common this level of drinking is. The study also suggests there's no evidence of a "safe" level of drinking with respect to cancer.

However, it's important to be aware that this review doesn't state how the author identified and assessed the research they've drawn upon. We don't know whether all relevant research has been considered and the conclusions must be considered largely the opinion of this single author.

Nevertheless, the main finding of the link between alcohol and these seven cancers is already well recognised.  Recently updated government recommendations state there's no safe level of alcohol consumption, and men and women are advised not to regularly drink more than 14 units a week. This review further supports this advice.

Where did the story come from?
The study was published in the peer-reviewed scientific journal Addiction. It is available on an open-access basis and is free to read online.

The study was published in the peer-reviewed scientific journal Addiction. It is available on an open-access basis and is free to read online.

Generally the media coverage of this topic was accurate, although the tone of the reporting tended to suggest this was a new discovery, when the link between alcohol and certain types of cancer is well established.

What kind of research was this?
This was a review which aimed to summarise data from published biological and epidemiological research, and meta-analyses that have pooled data, to evaluate the strength of evidence that alcohol causes cancer.

Alcoholic drinks have been considered potentially carcinogenic (cancer causing) for a while, but there are still concerns about the validity of some observational studies finding links with cancer, and uncertainty about precisely how alcohol causes cancer.

A systematic review is the best way of gathering and summarising the available research around a particular topic area. But in this case the exact methods are not described in the paper and it's not possible to say whether they were systematic.

There's a possibility that some relevant research may have been missed and that this review is giving an incomplete picture of the issue

What did the research involve?
The author of this review reports drawing upon biological and epidemiological research as well as meta-analyses conducted in the last 10 years by a number of institutions, including the World Cancer Research Fund and American Institute for Cancer Research, the International Agency for Research on Cancer and the Global Burden of Disease Alcohol Group.

The majority of epidemiological research seemed to come from cohort and observational studies.
The research was reviewed and summarised in a narrative format which explored the evidence that alcohol causes cancer, while contrasting this with the notion that alcohol consumption may offer some form of protection from cardiovascular disease.

No methods are provided and the author does not describe how they identified the research, as you would expect from a systematic review.  For example, they do not give the literature databases searched, the search dates, search terms, study inclusion or exclusion criteria, or descriptions of how studies were quality assessed.  

What were the basic results?
There were several findings from this study, the main one being that existing evidence supports the link between alcohol consumption and cancer at seven sites: oropharynx (mouth and throat), larynx (voice box), oesophagus (gullet), liver, colon (bowel), rectum and female breast.

The strength of the association differed by the site of the cancer. It was strongest for the mouth, throat and oesophagus, with the review suggesting that someone who drinks more than 50g of alcohol a day is four to seven times more likely to develop these types of cancer compared to someone who doesn't drink. As the author says, the interaction of smoking with alcohol is also believed to contribute to the risk of these cancers.

The link was comparatively weaker for colorectal, liver and breast cancer. The review suggests someone who drinks more than 50g of alcohol a day is 1.5 times more likely to develop these types of cancer compared to someone who doesn't drink.

For all of these associations there was a dose-response relationship, where increased consumption was linked with an increase in cancer risk. This applied to all types of alcoholic drinks. The highest risks were associated with heavier drinking. There was also some suggestion that the level of risk goes down over time when alcohol consumption stops.

Recent large studies have found uncertain evidence whether low to moderate consumption has a significant effect on total cancer risk. But given that this level of consumption is common in the general population, the author considers that it could still contribute to a significant number of cases.

Furthermore, they say there is no clear threshold of what constitutes a harmful level of alcohol consumption, and therefore no safe level of drinking with respect to cancer.

The author also suggests that confounding factors may be responsible for the protective effect between alcohol consumption and cardiovascular disease that has been found in previous studies. For example, this may be due to the potential bias caused by misclassification of former drinkers as abstainers.

The research went on to report that alcohol is estimated to be responsible for approximately half a million deaths from cancer in 2012 and 5.8% of cancer deaths worldwide, deeming it to be a significant public health burden.

How did the researchers interpret the results?
The author concluded: "There is strong evidence that alcohol causes cancer at seven sites, and probably others. The measured associations exhibit gradients of effect that are biologically plausible, and there is some evidence of reversibility of risk in laryngeal, pharyngeal and liver cancers when consumption ceases."

"The highest risks are associated with the heaviest drinking, but a considerable burden is experienced by drinkers with low to moderate consumption, due to the distribution of drinking in the population."

Conclusion
This narrative review aimed to summarise data from published biological and epidemiological research to discuss the strength of evidence that alcohol causes cancer.

The author gives their main finding as a link between alcohol consumption and cancer at seven sites, and also that the highest risks seem to be associated with heavier drinking. However, they state there's no "safe" drinking threshold and that low to moderate consumption still contributes to a significant number of cancer cases.

The biggest limitation of this review is that it doesn't appear to be systematic. The author provided no methods for how they identified and appraised the research they drew on. Despite referencing a number of large studies and reviews, this study and its conclusions have to be considered largely the opinion of the author following their appraisal of the evidence.

We don't know whether the review has considered all research relevant to the topic and is able to reliably quantify the risks of cancer – overall or at specific sites – associated with alcohol consumption.

An additional limitation to keep in mind is that this data mainly appeared to be from observational studies. These cannot prove cause and effect. The individual studies will likely have varied considerably in the additional health and lifestyle factors they took account of when looking at the links with alcohol. For example, smoking, diet and physical activity are all factors likely to be associated both with level of alcohol consumption and cancer risk.

As the author notes in particular, confounding factors may be responsible for the observed protective effect between alcohol consumption and cardiovascular disease.

Another limitation is that alcohol consumption is likely to be self-reported in the studies analysed, which may be inaccurate and lead to misclassification. For example, a potential bias that the author notes is classifying former drinkers as abstainers.

The author does consider the limitations of these observational findings, saying: "The limitations of cohort studies mean that the true effects may be somewhat weaker or stronger than estimated currently, but are unlikely to be qualitatively different."

But despite the methodological limitations of this review, it does support current understanding around this topic. Cancer Research UK also reports that alcohol can increase risk of these seven cancers and that there is no "safe" alcohol limit.

While we can't give a safe limit to drink when it comes to cancer, people are advised to follow current alcohol recommendations, which are to drink no more than 14 units per week and to spread your drinking over three days or more if you drink as much as 14 units a week.

Analysis by Bazian
Edited by NHS Choices

Links to the headlines
Even one glass of wine a day raises the risk of cancer: Alarming study reveals booze is linked to at least seven forms of the disease. Mail Online, July 22 2016
Alcohol is a direct cause of seven ​​forms of cancer, finds study. The Guardian, July 22 2016
Alcohol linked to at least seven types of cancer, study says, while 'health benefits are irrelevant'. The Telegraph, July 22 2016
Alcohol raises risk of seven different cancers, experts warn – even just one glass. Daily Mirror, July 22 2016
Alcohol causes seven types of cancer – and probably others, study finds. The Independent, July 22 2016

Links to the science

Connor J. Alcohol consumption as a cause of cancer. Addiction. Published online July 21 2016