Motivational effect of cholesterol measurement in general practice health checks.

A randomized trial was conducted in five general practices in and around Aylesbury, Buckinghamshire to assess the motivational effect of cholesterol measurement on compliance with advice to reduce dietary fat intake and to stop smoking. The advice was given by practice nurses during health checks for cardiovascular risk factors. A total of 578 patients were recruited to the study and randomized into two groups. Both groups were given the same advice and were followed up after a median of three months, but the intervention group was also given immediate feedback on their cholesterol concentration. Follow up was completed for 88.2% of subjects, and those who were not followed up were assumed not to have changed their behaviour. The mean fall in total cholesterol at follow up was 0.11 mmol l-1 (95% confidence interval 0.03 to 0.18) in the intervention group who were told their cholesterol result and 0.02 mmol l-1 (95% CI -0.06 to 0.10) in the control group who were not. The proportion of smokers who were not smoking at follow up was 10.7% and 10.1% in the two groups, respectively. Patients in the intervention group with an initial total cholesterol level of 6.50 mmol l-1 or greater showed a mean fall of 6.2% in cholesterol level whereas those with an initial cholesterol level of less than 5.20 mmol l-1 experienced a mean increase of 3.6%, but as differences of this magnitude were also seen in the control group they probably reflect regression to the mean rather than an effect of knowledge of cholesterol level.(ABSTRACT TRUNCATED AT 250 WORDS)