Pooled net change in systolic blood pressure ( 16 trials ) was -1.86 ( 95 % CI -3.17 to -0.55 ; p=0.01 ) mm Hg ; diastolic blood pressure ( 15 trials ) , -1.53 ( -2.43 to -0.62 ; p=0.001 ) mm Hg ; body mass index ( 14 trials ) , -0.13 ( -0.26 to -0.01 ; p=0.04 ) kg/m2 ; serum total cholesterol ( 14 trials ) , -0.13 ( -0.19 to -0.07 ; p<0.001 ) mmol/L. There was no significant association between interventions with a reported theoretical basis and improved intervention outcomes .
No association was observed between intervention intensity ( number of sessions and intervention duration ) and intervention outcomes .
MHBC interventions delivered to CVD-free participants in primary care did not appear to have quantitatively important effects on CVD risk factors .
BACKGROUND It is uncertain whether multiple health behaviour change ( MHBC ) interventions are effective for the primary prevention of cardiovascular disease ( CVD ) in primary care .
Multiple significance tests: the Bonferroni method.
Many published papers include large numbers of significance tests . These may be difficult to interpret because if we go on testing long enough we will inevitably find something which is “ significant . ” We must beware of attaching too much importance to a lone significant result among a mass of non-significant ones . It may be the one in 20 which we expect by chance alone . Lee et al simulated a clinical trial of the treatment of coronary artery disease by allocating 1073 patient records from past cases  into two “ treatment ” groups at r and om.1 They then analysed the outcome as if it were a genuine trial of two treatments . The analysis was quite detailed and thorough . As we would expect , it failed to show any significant difference in survival between those patients allocated to the two treatments . Patients were then subdivided by two variables which affect prognosis , the number of diseased coronary vessels and whether the left ventricular contraction pattern was normal or abnormal . A significant difference in survival between the two “ treatment ” groups was found in those patients with three diseased vessels ( the maximum ) and abnormal ventricular contraction . As this would be the subset of patients with the worst prognosis , the finding would be easy to account for by saying that the superior “ treatment ”
Pooled net change in systolic blood pressure ( 16 trials ) was -1.86 ( 95 % CI -3.17 to -0.55 ; p=0.01 ) mm Hg ; diastolic blood pressure ( 15 trials ) , -1.53 ( -2.43 to -0.62 ; p=0.001 ) mm Hg ; body mass index ( 14 trials ) , -0.13 ( -0.26 to -0.01 ; p=0.04 ) kg/m2 ; serum total cholesterol ( 14 trials ) , -0.13 ( -0.19 to -0.07 ; p<0.001 ) mmol/L. There was no significant association between interventions with a reported theoretical basis and improved intervention outcomes .
No association was observed between intervention intensity ( number of sessions and intervention duration ) and intervention outcomes .
MHBC interventions delivered to CVD-free participants in primary care did not appear to have quantitatively important effects on CVD risk factors .
BACKGROUND It is uncertain whether multiple health behaviour change ( MHBC ) interventions are effective for the primary prevention of cardiovascular disease ( CVD ) in primary care .