Research highlights – 11 November 2011

Research questions“Research highlights” is a weekly round-up of research papers appearing in the print BMJ. We start off with this week’s research questions, before providing more detail on some individual research papers and accompanying articles.

Exercise referral schemes: a case for disinvestment?
We have guidance on how much exercise to do, how often, what the health benefits are, and how to adapt exercise in disease and at different times of life. But how should doctors help their patients to meet these targets? Should they give advice, give leaflets, or use specific exercise referral schemes?

In 2006 there was insufficient evidence to support exercise referral schemes, according to the UK National Institute for Health and Clinical Excellence. But they called for more trials to investigate how good the schemes were. In their systematic review, Toby Pavey and colleagues examine whether such schemes have increased exercise or improved health outcomes.

Interpreting their findings is challenging because of heterogeneity; schemes and their outcomes differed, and some were of poor quality. Despite small increases in short term exercise and a reduced level of depression, Pavey’s team seem unconvinced that exercise referral schemes are worth it. Similar improvements can be achieved by brief advice and written materials provided by a general practitioner, writes Nefyn Williams in a linked editorial. Where does that leave referral schemes at a time when finances are limited?

Given these new findings, doctors may feel more inclined to revisit some recent publications, such as Karim Khan and colleagues’ list of 10 practical steps on how to prescribe exercise (BMJ 2011;343:d4141). It links to other helpful resources, such as a Swedish physical activity guide, and websites containing useful patient information leaflets about exercise for those with specific diseases. Useful to bookmark for patients inspired to exercise in the run-up to the London Olympics.

Men’s experiences of erectile dysfunction after treatment for colorectal cancer
“I presumed it to be an effect of chemotherapy which surprised me, I did some Googling and found that it was in fact most likely an effect from the surgery and to be honest I was annoyed that I didn’t know about it,” explained one man in this qualitative interview study by George Dowswell and colleagues. Another, aged 72 reported: “He said ‘at your age I don’t think it will matter’ and he was nearly as old himself (Laughs) I thought ‘that’s a bloody cheek.’ You know, I said to myself ‘well he’s nearly as old as me.’”

Such reports of ageism and inadequately informed surgical consent make uncomfortable reading. The authors rightly avoid extrapolating too far from their interview study with 28 men, but they don’t pull their punches. Given these qualitative findings, and the same team’s earlier survey showing that 75% of men report erectile dysfunction after treatment for colorectal cancer (J Sex Med 2010;7:1488-96), the authors conclude in their BMJ pico summary that “most men with colorectal cancer develop erectile dysfunction after treatment. This paper suggests that clinicians are inadvertently neglecting, misleading, and offending such patients.”

In a linked editorial colorectal surgeon Larissa Temple notes the study’s limitations, but says it has generated important hypotheses for future research. She also calls for clinical practice guidelines on identifying and managing functional problems after treatment for colorectal surgery. Disappointingly, this week’s summary of NICE guidance on the diagnosis and management of colorectal cancer doesn’t mention erectile dysfunction among the harms of treatment.

Dietary fibre, whole grains, and risk of colorectal cancer
Dagfinn Aune and colleagues’ systematic review and meta-analysis found that high intake of dietary fibre, in particular cereal fibre and whole grains, was associated with a reduced risk of colorectal cancer. They found no significant evidence of an association with intake of fibre from fruit, vegetables, or legumes.

Prognostic effect size of cardiovascular biomarkers in datasets from observational studies versus randomised trials
Cardiovascular biomarkers often have less promising results in the evidence derived from randomised controlled trial populations than from observational studies, report Ioanna Tzoulaki and colleagues.

Comparison of range of commercial or primary care led weight reduction programmes with minimal intervention control for weight loss in obesity
In the “Lighten Up” randomised controlled trial, Kate Jolly and colleagues found that commercially provided weight management services were more effective and cheaper than primary care based services led by specially trained staff.