Behavioural counselling in general practice about risk of CHDBMJ 2000; 321 doi: https://doi.org/10.1136/bmj.321.7252.49/b (Published 01 July 2000) Cite this as: BMJ 2000;321:49
Study was grossly underpowered
- F D Richard Hobbs, head of division (email@example.com)
- Division of Primary Care, Public and Occupational Health, Department of Primary Care and General Practice, University of Birmingham, Medical School, Birmingham B15 2TT
- Department of Nutrition and Dietetics, Hammersmith Hospital, London W12 0HS
- Department of Epidemiology and Public Health, Imperial College School of Medicine, Hammersmith Campus, London W12 OHS
- Department of Social Medicine, University of Bristol, Bristol BS8 2PR
- Frenchay Hospital, Bristol BS16 1LE
- Department of Psychology, St George's Hospital Medical School, London SW17 0RE
- Department of General Practice and Primary Care, St George's Hospital Medical School, London SW17 0RE
EDITOR—Steptoe et al draw unreliable conclusions from their randomised controlled trial of a brief behavioural counselling intervention, led by nurses, to promote healthy behaviour among adults at increased risk of coronary heart disease.1 Because of considerable difficulties in recruitment and retention the study is grossly underpowered, with only 316 intervention patients and 567 control patients recruited against the required target of 2000. The authors cannot therefore report that “brief counselling on the basis of systematic applications of behavioural principles is more efficacious in stimulating lifestyle modification than conventional counselling.”
The authors have further overinterpreted these unreliable data, since the only changes in behaviour were self reported reductions in dietary fat intake and number of cigarettes smoked and increases in physical activity. Objective measurements, such as body mass index, weight, blood pressure, and smoking cessation (validated by cotinine assay), did not change. Given the unreliability of self reporting as a primary outcome, it is inappropriate to draw positive conclusions.
Furthermore, the authors conclude that “there may be an important role for this counselling” among hard pressed service practitioners and that “more extended counselling … may be required.” These seem extraordinary assertions given the negative findings from the study. The authors also ignore their own findings that this “brief” intervention was actually rather substantial: nurse training took four days, and counselling sessions lasted up to 20 minutes on two or three occasions, with one or two follow up telephone calls. This is a considerable time commitment, and the researchers were able to get nurses to recruit only one third of patients needed in intervention practices. In addition, it is inappropriate for researchers to make recommendations on the implications for service practice without conducting any sort of economic analysis.
Given the wealth of unequivocally evidence based interventions that help to reduce coronary …