bmj.com: Research

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Mortality from pandemic A/H1N1 2009 influenza in England

Viewed statistically, mortality in this pandemic compares favourably with 20th century influenza pandemics. A lower population impact than previous pandemics, however, is not a justification for public health inaction. The data from this study support the priority vaccination of high risk groups. Given that a substantial minority of deaths occur in previously healthy people, there is a case for extending the vaccination programme.

The truth about Tamiflu?

This Cochrane group's update of a 2005 review of oseltamivir in pandemic influenza concludes: "Neuraminidase inhibitors have modest effectiveness against the symptoms of influenza in otherwise healthy adults. The drugs are effective postexposure against laboratory confirmed influenza, but this is a small component of influenza-like illness, so for this outcome neuraminidase inhibitors are not effective. Neuraminidase inhibitors might be regarded as optional for reducing the symptoms of seasonal influenza. Paucity of good data has undermined previous findings for oseltamivir's prevention of complications from influenza. Independent randomised trials to resolve these uncertainties are needed."

A cluster of articles on bmj.com seeks to elucidate problems with the data that have underpinned the use of oseltamivir in healthy adults with pandemic influenza. Deborah Cohen retraces the steps of the Cochrane reviewers as they tried to obtain all the relevant data and finds that commitments to transparency are still in doubt. Peter Doshi explains that the public evidence base for this global public health drug is fragmented and inconsistent. And Nick Freemantle and Mel Calvert find that observational studies of oseltamivir's efficacy show minimal benefit. In an accompanying editorial, Fiona Godlee and Mike Clarke say that the full data from drug trials must be available for scrutiny by the scientific community.

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Also new on pandemic flu:

Swine flu: interview with Sir Liam Donaldson, chief medical officer

Survivors of childhood cancer

According to this analysis of the Childhood Cancer Survivor Study cohort, survivors of childhood and adolescent cancer are at substantial risk for cardiovascular disease. Healthcare professionals must be aware of these risks when caring for this growing population. In the accompanying editorial, Meriel Jenney and Gill Levitt say that numbers of childhood cancer survivors are increasing, so a network of specialists that crosses age boundaries is needed.

Duration and magnitude of the postoperative risk of venous thromboembolism in middle aged women

According to this study, the increased risk of venous thromboembolism reached a peak in the third postoperative week and remained substantially increased up to 12 weeks after surgery. During the 12 weeks after surgery 1 in 140 middle aged UK women were admitted to hospital with venous thromboembolism after an inpatient operation, and 1 in 815 after day case surgery; this compares with only 1 in 6200 admitted with venous thromboembolism during a 12 week period without surgery. Thromboprophylaxis should cover a wider group of patients, and possibly for longer than currently recommended, says an accompanying editorial. Image: SPL.

Risk of cardiovascular disease and all cause mortality among patients with type 2 diabetes prescribed oral antidiabetes drugs

Compared with metformin (pictured), monotherapy with first or second generation sulphonylureas was associated with a significant excess risk of all cause mortality, and second generation sulphonylureas with an excess risk of congestive heart failure, says this retrospective cohort study using the UK general practice research database. The thiazolidinediones were not associated with a risk of myocardial infarction; pioglitazone was associated with a significantly lower risk of all cause mortality compared with metformin, it adds. Image: SPL.

Effect of a very low energy diet on moderate and severe obstructive sleep apnoea in obese men

After nine weeks, the study showed a 67% reduction in apnoea hypopnoea index (AHI) in the group allocated to very low energy diet, with the greatest effect seen in patients with severe disease, whereas no change occurred in the weight stable control group, according to this randomised controlled trial. Well designed clinical trials are needed to convince policy makers, patients, and practising clinicians of the long term usefulness of tailored approaches, says an accompanying editorial. Image: SPL.

Multiple sclerosis risk sharing scheme

This prospective cohort study with historical comparator aimed to generate evidence on the longer term cost effectiveness of disease modifying treatments in patients with relapsing-remitting multiple sclerosis. However, the researchers found that it is too early to reach any conclusion about the cost effectiveness of disease modifying treatments from this first interim analysis. Important methodological issues will need to be addressed, and long term follow-up of all patients is essential to secure meaningful results.

Are people with negative diabetes screening tests falsely reassured?

According to this randomised controlled trial, a negative test result at diabetes screening does not seem to promote false reassurance, whether this is expressed as lower perceived risk, lower intentions for health related behavioural change, or higher self rated health. Implementing a widespread programme of primary care based stepwise screening for type 2 diabetes is unlikely to result in unhealthy behaviours among people who screen negative.

Quality of life three years after diagnosis of localised prostate cancer

This population based cohort study found that the various treatments for localised prostate cancer each have persistent effects on quality of life. Sexual dysfunction three years after diagnosis was common in all treatment groups, whereas poor urinary function was less common. Bowel function was most compromised in those who had external beam radiotherapy. The authors recommend that men with prostate cancer and the clinicians who treat them should be aware of the effects of treatment on quality of life, and weigh them up against the patient�s age and the risk of progression of prostate cancer if untreated to make informed decisions about treatment.

Prospective associations between objective measures of physical activity and fat mass in 12-14 year old children

This longitudinal study found that higher levels of physical activity, in particular activity of moderate to higher intensities, are prospectively associated with lower levels of fat mass in early adolescence. Interventions to raise levels of physical activity in children are likely to be important in the fight against obesity.