A cluster randomised controlled trial of vascular risk factor management in general practice

To the Editor: Harris and colleagues report failure to obtain reduction in several important risk factor-based intermediate outcomes for vascular disease from their lifestyle intervention in the Health Improvement and Prevention Study (HIPS).1 Using intention-to-treat analysis, if only 117 of 384 participants completed at least two of six group sessions, a positive result could not be expected. We know that interventions for prevention of cardiovascular disease (CVD) and diabetes can be run successfully in Australian primary care, which raises questions about the design of Harris et al’s intervention.