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Welcome to the BMJ Open blog. BMJ Open is an open access journal, dedicated to publishing medical research from all disciplines and therapeutic areas.

Find out more about the journal here.

We will be updating the blog with news about the journal, highly accessed papers, press coverage, events and matters of interest in the open access and publishing world, and anything else that catches our eye.

#BMJOpen5years: 2013 article highlights

25 Feb, 16 | by aaldcroft

This week we’re celebrating our fifth anniversary by highlighting some of the articles that have gained us attention, along with some that demonstrate our unique approach. 

For 2013, we’d like to present two articles along with some key statistics.

Do healthier foods and diet patterns cost more than less healthy options? A systematic review and meta-analysis

Conclusions: This meta-analysis provides the best evidence until today of price differences of healthier vs less healthy foods/diet patterns, highlighting the challenges and opportunities for reducing financial barriers to healthy eating.

Key statistics:

  • Cited 41 times in Web of Science
  • Over 55,000 total full text and PDF downloads
  • Altmetric score of 708


A school-based education programme to reduce salt intake in children and their families (School-EduSalt): protocol of a cluster randomised controlled trial

BMJ Open strongly believes in the importance of publishing study protocols. Published in 2013, this protocol from China presents the methods for a cluster randomised control trial where children receive an educational intervention to reduce salt intake. Children are then asked to bring the salt reduction message home to educate their families.

Results were published in 2015 in The BMJ.

#BMJOpen5years: 2012 article highlight

24 Feb, 16 | by aaldcroft

Hypnotics’ association with mortality

This week we’re celebrating our fifth anniversary by highlighting some of the articles that have gained us attention, along with some that demonstrate our unique approach. 

Cited 66 times in Web of Science and with an Altmetric score of 480, “Hypnotics’ association with mortality or cancer: a matched cohort study” is certainly one of the most influential papers ever published in BMJ Open. Using a database including more than 10,000 patients, the study from Daniel Kripke and colleagues highlighted an association between sleeping pills and mortality.


We wrote to Dr Kripke to comment on the impact his article has had around the world:

“Publishing in BMJ Open was very satisfying, since the review was fast and fair, editing done well, and publication rapid and accessible.  The press release was remarkably effective.  In 50 years of research, I have never had an article covered so widely:  not only in European and North American media, but also in Japan, China, Thailand, even Myanmar, Bali, Yemen, and Ruanda.

“The important result, four years later, is at least 50 new studies of hypnotics risks, most of which mention our work.  This growing scientific focus is confirming and defining the risks of hypnotics more clearly.  I was particularly happy with Weich et al. that largely replicated our results in an even better-done study of a larger group, and Palmaro et al. that clarified how short-term hypnotics exposures have particularly high risk ratios.  New British and Taiwan studies have expanded the evidence for severe infection risks of hypnotics, a phenomenon that requires much more clinical and laboratory exploration.”

Also of note is the extensive post-publication discussion, along with extensive mentioning on Twitter that continues four years later.

Dr Kripke notes,

“In BMJ Open, the lively COMMENTS section response was very helpful in clarifying scientific critiques of our work, some of which I had the opportunity to rebut, and in disclosing the public emotional reactions that we need to understand for public health interventions.”

#BMJOpen5years: 2011 article highlight

24 Feb, 16 | by aaldcroft

Uses and misuses of the STROBE statement


This week we’re celebrating our fifth anniversary by highlighting some of the articles that have gained us attention, along with some that demonstrate our unique approach. 

The use of reporting guidelines has always been central to BMJ Open, and we’re happy to see that one of the articles published in our very first edition, back in February 2011, is also one of our most highly cited.

Uses and misuses of the STROBE statement  has been cited more than 60 times in the Web of Science. By reviewing the literature, Bruno da Costa and colleagues highlight how correctly to use reporting guidelines and how the guidelines are often misused to assess methodological quality rather than the quality of the reporting.

So what might explain the misuse of the guidelines? According to da Costa et al.,

“The misuse of STROBE as a tool to assess methodological quality may be explained by the lack of validated and accepted tools for such assessments. As a consequence, authors who want to assess methodological quality of studies may turn to reporting guidelines.”

While the message is simple, it is also important, and we believe the article deserves its place as one of the journal’s highlights. It was also the first among many articles that we have published relating to medical publishing and peer review.

Five years old and growing

23 Feb, 16 | by aaldcroft

Five years ago today, BMJ Open appeared on the scene. Conceived as a general medical journal to provide authors a fast, transparent route to publication, BMJ Open could have developed in many different ways. Happily it has developed into a journal we’re proud of, and despite its broad scope, it has grown into a journal with a strong identity. Publishing 230 articles in our first year, our growth has been steady and consistent, and we have increased our global presence every year. In 2015 we published over 1,500 articles from 70 countries. We have carved out a niche in qualitative research and the publication of study protocols and articles less likely to be accepted in traditional medical journals. 

Number of accepted papers

Importantly, as exemplified in our use of open peer review and the publication of reviewers’ reports, we have embraced the notion that research should be open and transparent. Just as importantly, we have a strong belief in the importance of sound methodology, asking authors to state clearly, up front, the methodological strengths and limitations of their study. We believe objectivity takes precedence over novelty and require our authors to adhere to the standards of reporting promoted by the EQUATOR network. Through these guiding principles, we have become, in only five years, the world’s largest general medical journal.

Now seems a good time to reflect upon what we have achieved, and where we would like to go. To celebrate, over the next few days we will be highlighting on our blog articles that have gained significant attention, along with articles that demonstrate our unique approach.

But, of course, there is still much work to be done. Looking into the future, we hope to continue down the path we are on, growing and developing, particularly in parts of the world that have historically been underrepresented in the medical literature. Global initiatives, such as BMJ’s China portal, will become increasingly important to us. We also hope to continue our efforts to make data more available and accessible, the importance of which has recently been stressed with the public health emergency surrounding the Zika virus. While we have made strong efforts by fully integrating our system with Dryad, we have only scratched the surface.

Most of all we want to thank the authors, reviewers, and readers who have made it all possible. Please join us in celebrating our first five years!

Membership of social/community groups after retirement linked to longer life

16 Feb, 16 | by Fay Pearson

Membership of social groups, such as book clubs or church groups, after retirement is linked to a longer life, with the impact on health and wellbeing similar to that of regular exercise, suggests research published in the online journal BMJ Open.

The more groups an individual belongs to in the first few years after s/he stops working, the lower their risk of death, the findings show.

Retirement represents a major life change, with the evidence from large long-term studies suggesting that the health and wellbeing of a substantial number of retirees goes downhill after they stop formal work.

But some people adjust to this transition better than others. In a bid to assess the potential impact of social group memberships, the researchers tracked the health of 424 people for six years after they had retired.

They were compared with the same number of people, matched for age, sex, and health status, but who were still working.

All the participants were at least 50 years old, living in England, and taking part in the English Longitudinal Study of Ageing, which started in 2002-3.

Each participant was asked how many different organisations, clubs, or societies, s/he belonged to, and which ones. They were also asked to complete a validated scale to assess quality of life, and another, to assess subjective physical health.

The results showed that individuals whose quality of life was good before retirement were more likely to score highly on quality of life assessment after retirement.

But membership of social groups was also associated with quality of life. Compared with those still working, every group membership lost after retirement was associated with around a 10% drop in quality of life score six years later.

Some 28 (6.65%) of the retirees died in the first six years after stopping work. Unsurprisingly, the strongest predictor of death was age, with someone at the age of 55 running a 1% risk of dying compared with an 8% chance for someone aged 65.

Subjectively rated health was not a significant predictor of death, but the number of group memberships was.

If a person belonged to two groups before retirement, and kept these up over the following six years, their risk of death was 2%, rising to 5% if they gave up membership of one, and to 12% if they gave up membership of both.

No such patterns were seen for those still in formal employment.

The researchers separately assessed whether changes in physical activity levels affected risk of death and compared this with the magnitude of the effect of social group membership.

They found that if a person exercised vigorously once a week before retirement, and kept up this frequency afterwards, their chance of dying over the next six years was 3%, rising to 6% if they reduced the frequency to less than once a week, and to 11% if they stopped altogether.

Among those who were still working, the equivalent figures were 3%, 5%, and 8%.

“Accordingly, we can see that the effects of physical activity on health were comparable to those associated with maintaining old group memberships and developing new ones,” write the researchers.

This is an observational study so no firm conclusions can be drawn about cause and effect, but the findings have unique practical implications for retirement planning, say the researchers.

“They suggest that as much as practitioners may help retirees adjust by providing support with financial planning, they may also help by providing social planning,” they write.

“In this regard, practical interventions should focus on helping retirees to maintain their sense of purpose and belonging by assisting them to connect to groups and communities that are meaningful to them,” they conclude.

Higher nurse to patient ratio linked to reduced risk of inpatient death

9 Feb, 16 | by Emma Gray

Death rates 20 per cent lower in hospitals with 6 or fewer patients per registered nurse

A higher nurse to patient ratio is linked to a reduced risk of inpatient death, finds a study of staffing levels in NHS hospitals, published in the online journal BMJ Open.

In trusts where registered (professionally trained) nurses had six or fewer patients to care for, the death rate was 20 per cent lower than in those where they had more than 10.

Policies geared towards substituting registered nurses with healthcare support workers (healthcare assistants and nursing auxiliaries) should at the very least be reviewed, conclude the researchers

Previous research suggests that the nurse to patient ratio has some bearing on outcomes, but few studies have taken account of the impact of other members of medical staff.

They therefore included two measures over two years (2009-11) in their analysis: the number of beds per registered nurse, doctor, and healthcare support worker in 137 acute care trusts; and the number of patients per ward nurse, drawn from a survey of just under 3000 registered nurses in a nationally representative sample of 31 of these trusts (covering 46 hospitals and 401 wards).

They also calculated the predicted number of deaths for medical and surgical inpatients, taking account of influential factors, such as age, other underlying conditions, and number of emergency admissions during the previous 12 months.

The registered nurse headcount varied by as much as a factor of 4 between those at the top and bottom of the staffing scale. Even after taking account of all nursing staff, this variation only dropped to a threefold difference between those with the highest and lowest nurse headcounts.

Among patients admitted to medical wards, higher death rates were associated with higher numbers of occupied beds for each registered nurse and for each doctor employed by the trust.

By contrast, higher numbers of healthcare support workers were associated with higher rates of inpatient death.

When all staff groups were included in the statistical analysis of all 137 trusts, the associations remained significant only for doctors and healthcare support workers.

Among the subsidiary group of 31 trusts, death rates were 35.2/1000 medical admissions, out of a total of 1 260, 558, and 8.9/1000 surgical admissions, out of a total of 1 084 429.

But the death rate was 20% lower in those where each registered nurse cared for an average of six or fewer medical inpatients than in trusts were each registered nurse cared for 10 or more. These associations remained significant after further statistical analysis.

The results on surgical wards were similar, with higher registered nurse to patient ratios associated with a 17% lower inpatient death rate.

This is an observational study, so no firm conclusions can be drawn about cause and effect, added to which the findings on nurse to patient ratios are based on only 31 trusts.

“This [study] does not, in itself, provide a robust basis to identify safe staffing thresholds,” they say. “However, given the overall strength of evidence for an association, it does seem feasible to identify staffing levels where risk to patients is likely to be increased,” they suggest.

Economic pressures and the ageing profile of the nursing workforce internationally all point to a potential future with fewer registered nurses, they warn. But substituting them for less well trained staff may be unwise, they say.

“When determining the safety of nurse staffing on hospital wards, the level of registered nurse staffing is crucial, and there is no evidence to suggest that higher levels of healthcare support worker staffing have a role in reducing mortality rates,” they write.

“Current policies geared towards substituting [these] workers for registered nurses should be reviewed in the light of this evidence,” they conclude.

A podcast for this manuscript is available to listen to here:

The NHS Health Check in England, bereavement by suicide, and public involvement in medical research: Most read articles in January

5 Feb, 16 | by Emma Gray

NHS Health Checks, the risks of bereavement by suicide, and public involvement in medical research


The Top 10 Most Read list for January is almost completely comprised of new entries, with the exception of the ever popular review by Kristensen et al on the effects of statins. In the top spot this month is an evaluation of the first four years of the NHS Health Check in England, by Robson et al. At number two we have a cross-sectional study seeking to test the hypothesis that young adults bereaved by suicide have an increased risk of suicidal ideation and suicide attempt compared to their peers bereaved by other sudden deaths. Parsons et al enter the list at number five with a paper asking what pharmaceutical industry professionals believe about public involvement in medicines research and development, and Joost et al enter at number eight with a paper on persistent spatial clusters of high body mass index.

Rank Author(s) Title
1 Robson et al. The NHS Health Check in England: an evaluation of the first 4 years
2 Pitman et al. Bereavement by suicide as a risk factor for suicide attempt: a cross-sectional national UK-wide study of 3432 young bereaved adults
3 Kristensen et al. The effect of statins on average survival in randomised trials, an analysis of end point postponement
4 Carey et al. Systems science and systems thinking for public health: a systematic review of the field
5 Parsons et al. What do pharmaceutical industry professionals in Europe believe about involving patients and the public in research and development of medicines? A qualitative interview study
6 Friis et al. Gaps in understanding health and engagement with healthcare providers across common long-term conditions: a population health survey of health literacy in 29 473 Danish citizens
7 Ovseiko et al. Markers of achievement for assessing and monitoring gender equity in translational research organisations: a rationale and study protocol
8 Joost et al. Persistent spatial clusters of high body mass index in a Swiss urban population as revealed by the 5-year GeoCoLaus longitudinal study
9 Parsons et al. ‘Please don’t call me Mister’: patient preferences of how they are addressed and their knowledge of their treating medical team in an Australian hospital
10 Greenhalgh et al. Virtual online consultations: advantages and limitations (VOCAL) study

Most read figures are based on pdf downloads and full text views. Abstract views are excluded.

Requesting clinical trial protocols

19 Jan, 16 | by Fay Pearson

We have recently made some changes to our submission system. If we receive a clinical trial, we will now ask that authors include the original trial protocol. Editor-in-chief, Dr Trish Groves, explains why:

Transparent reporting of research has always been at the heart of BMJ Open. From the very start the journal has published all research with open access, open peer review, and sometimes – when authors opt for sharing via the Dryad repository – open data.

Openness is specially important for clinical trials, and that’s why we are now requiring that trialists submit the study protocol to BMJ Open along with their paper:

  • This should be the version of the protocol that gained ethics approval and was used to run the trial
  • If the protocol was amended between getting ethics approval and starting the trial, the authors must say why in their cover letter
  • The submitted protocol should be labelled with a version number and should include a history of substantive amendments, giving the dates when amended
  • If the trial protocol has been published in an open access journal, and if that published version includes all the information and dates as listed above, then authors can simply provide BMJ Open with the reference and link to the published protocol
  • If BMJ Open publishes the submitted trial, the protocol will be posted alongside as part of the pre-publication history

Why is BMJ Open now requiring protocols? For clinical trials (and protocols for clinical trials) BMJ Open has always required prospective registration, and we ask authors to give the trial’s registration ID in the paper’s abstract. This allows editors, peer reviewers, and ultimately readers to see a summary of the planned design of the trial and to compare it with the paper that reports the trial’s results. And dates in the registration record allow us to check that the trial was, indeed, registered prospectively – before any patients were enrolled. Isn’t this enough? Not quite. Trial registration provides a lot of useful information about a planned study, but registries have space only for a minimum of key information.

You can’t interpret the results of a clinical trial without fully understanding how the study was planned, designed, and conducted. Yet it’s all too common for methods to be reported selectively, partly, or not at all. And it has become clear that registration does not always prevent this, particularly when it comes to outcome switching.  Too often, prespecified outcomes are not reported, and others are added and reported in analyses that may not be valid. By making trial protocols available when trial results are reported in BMJ Open, we can all help to optimise the evidence base for treatments and other interventions.

Editors’ Picks 2015: Part Seven

10 Jan, 16 | by Ed Sucksmith

Polypharmacy and potentially inappropriate prescription of medicines


This week we have been looking at some of our staff editors’ favourite articles from 2015. These papers have covered a variety of important issues in medical research, from the transparency of clinical trials to the publication of negative findings. Our final editors’ pick takes us to Ireland, where Professor Tom Fahey and colleagues from the Royal College of Surgeons in Dublin looked at pharmacy claims data to investigate long-term trends in prescribing of medicines between 1997 and 2012. Their findings included the positive news that prescribing quality had improved across the time period. However, there was a substantial increase in the number of people taking multiple regular medicines (known as ‘polypharmacy’), and this significantly predicted potentially inappropriate prescription of medicines. The authors suggested that patients should be made more aware of the trade-off between taking more medicines to prevent disease and the potential for harm from potentially inappropriate prescribing of drugs, which is associated with taking more medicines.

Editors’ Picks 2015: Part Six

9 Jan, 16 | by Ed Sucksmith

The 2D:4D digit ratio and autism risk: is there an association?


In December we surveyed our staff editors to tell us about their favourite articles from 2015. Our penultimate editors’ pick investigates the relationship between autism risk and a putative marker of testosterone exposure: the 2D: 4D digit ratio.

In spite of large investments in autism research, the underlying causes of autism diagnoses remain largely unknown, although twin and family studies suggest that autism is highly heritable. Perplexingly, autism is more frequently diagnosed in males, with male-to-female ratio estimates ranging from 2:1 to 9:1. A popular theory put forward to explain the sex differences behind autism diagnoses is the ‘Extreme Male Brain theory’, which proposes that people with autism are exhibiting an exaggerated profile of the male cognitive profile. A proposed physiological mechanism underlying this theory is the effect of prenatal sex steroids (such as testosterone) on the developing brain. The index to ring finger ratio (2D:4D digit ratio) is believed to be a proxy for fetal testosterone exposure; males have a lower 2D:4D digit ratio on average than females.

In this study by Anna Guyatt and colleagues, the 2D:4D digit ratio was examined in 6015 children from a British birth cohort known as The Avon Longitudinal Study of Parents and Children. The 2D:4D digit ratio was then tested for association with autistic traits in the general population and with autism diagnoses. Analysis of the data did not indicate a significant association between 2D:4D digit ratio and autism diagnoses or high autistic traits in the general population for either sex. Thus, the data did not support the extreme male brain theory of autism.

The study is just one of many published in BMJ Open in 2015 reporting negative findings. We believe that a study should be published irrespective of the direction of the findings providing that the study meets our publication criteria. Publishing negative findings has the added benefit of combating the damaging effects of dissemination bias in medical research (see Editors’ Picks 2015: Part Three)