One step forward, two steps back?

Ideas that have promise but don’t quite deliver seem to be a theme in this week’s issue. First comes detailed information on genetic risks. Gareth Hollands and colleagues did a cluster randomised trial to see if providing a DNA based risk assessment to people at risk of Crohn’s disease increased the likelihood of them giving up smoking, which can affect this risk (doi:10.1136/bmj.e4708). It didn’t. In their accompanying editorial, Liam Smeeth and Tjeerd van Staa commend this attempt to study the effect of genetic information in a randomised trial, but they point out that the increased risk of Crohn’s disease conferred by the particular genetic variants is dwarfed by the effect of having a first degree relative with the disease (doi:10.1136/bmj.e4651). Once again the extra information provided by genetic analyses of common diseases doesn’t seem to be quite enough to make an important difference.

The second idea that gets short shrift is “pay for performance.” Paul Glasziou and colleagues reviewed evidence on the positive and negative effects of financial incentives in changing clinical behaviour and devised a checklist of things to consider before deciding to implement a pay for performance scheme (doi:10.1136/bmj.e5047). Interestingly, none of the well known schemes from Australia, the United Kingdom, and the United States tick all the boxes. In an editorial Steffie Woolhandler and colleagues discuss the evidence that such schemes undermine honesty and motivation (doi:10.1136/bmj.5015). Not only do these systems invite “gaming,” such as over-investigation to find unimportant comorbidities and “upcoding” of conditions, they may also “undermine the intrinsic motivation crucial to maintaining quality when nobody is looking.”

But there are more positive findings elsewhere in the issue. In his feature on the 19th international AIDS conference in Washington, Bob Roehr describes the upbeat mood driven by the vast expansion in the numbers of people being treated for HIV infection, a renewed interest in the search for a cure, and hopeful talk of eradication and early intervention (doi:10.1136/bmj.5265). Yet Doug Kamerow remains doubtful about talk of an AIDS free world (doi:10.1136/bmj.e5479). Even if all HIV positive people were identified and started on treatment, he says in his Observations article, “it still would not spell the end of the HIV story . . . We have no vaccine and the virus keeps mutating.”

In the wake of the Olympics it’s perhaps appropriate that something as simple as exercise should feature as an important intervention for two common conditions. A Clinical Review (doi:10.1136/bmj.e5208) and a summary of NICE guidance (doi:10.1136/bmj.e4947) on peripheral artery disease both emphasise the strong evidence for offering supervised exercise programmes to everyone with intermittent claudication. And Lindy Clemson and colleagues show that some types of exercise can prevent falls (doi:10.1136/bmj.e4547). They randomised people aged over 70 to a control programme of gentle exercise, to structured exercise three times a week, or to a programme of balance and strength training integrated into everyday activities. The group that exercised as part of their everyday activities had significantly fewer falls, whereas the structured exercise group had only a non-significant reduction. In her accompanying editorial (doi:10.1136/bmj.e4919), Meg Morris suggests that embedding exercise in everyday activities is likely to increase adherence and ensure that “enough dosage of the intervention is delivered.”