bmj.com: Research

The BMJ (Impact Factor 12.8) provides open access to peer reviewed research as part of its commitment to readers and authors. We make all BMJ research articles freely available online, with no word limit, and send them directly to PubMed Central (the National Library of Medicine's full text archive). For details on how to submit articles, visit our resources for authors.

Carbon cost of pragmatic randomised controlled trials

CO2 emissions generated by randomised controlled trials can be reduced. A large proportion of the CO2 emissions come from travel related to various aspects of a trial. Further research is needed to explore the additional CO2 emissions generated by clinical trials, over and above those generated by routine care.

Evaluating the causal relevance of diverse risk markers

This horizontal systematic review pinpoints deficiencies and strengths in the evidence for depression, exercise, C reactive protein, and diabetes as unconfounded and unbiased causes of coronary heart disease. This new method could be used to develop a field synopsis and prioritise future development of guidelines and research.

Implementation of the Canadian C-Spine Rule: prospective 12 centre cluster randomised trial

This study shows that implementing of the Canadian C-Spine Rule led to a significant decrease in imaging without injuries being missed or patient morbidity. Final imaging rates were much lower at intervention sites than at most US hospitals. The researchers say that widespread implementation of this rule could lead to reduced healthcare costs and more efficient patient flow in busy emergency departments worldwide. The linked editorial says that the success of implementation will depend on every member of the team being trained in how to use the rule, including triage nurses in emergency departments and paramedics.

Other new research:

Effect of tailored practice and patient care plans on secondary prevention of heart disease in general practice

Immobilisation versus immediate mobilisation after intrauterine insemination

Women who lie on their backs for 15 minutes after artificial insemination have a "significantly higher" chance of getting pregnant than women who move around straight after treatment, according to this study. The authors say that immobilisation for 15 minutes should be offered to all women treated with intrauterine insemination. Editorialist William Ledger says that this shows promise in increasing pregnancy rates, but further studies are needed.

Reliability of self reported smoking status by pregnant women for estimating smoking prevalence

According to this study, reliance on self reporting to identify pregnant smokers significantly underestimates the number of pregnant smokers in Scotland. It means that more than 2400 smokers each year escape detection and therefore cannot be offered help to quit.

Migraine and cardiovascular disease

Migraine is associated with a doubled risk of ischaemic stroke, which is only apparent among people who have migraine with aura. The results of this study also suggest a higher risk among women, and risk was further magnified for people with migraine who were younger than 45, smokers, and women who used oral contraceptives. The researchers did not find an overall association between any migraine and myocardial infarction or death due to cardiovascular disease. Editorialist Elizabeth Loder says that patients should be treated aggressively for modifiable cardiovascular risk factors.