Trial was underpowered

EDITOR—The paper reporting the trial to improve follow up in general practice of patients with coronary heart disease after discharge from hospital is unduly pessimistic.1 At least one of the authors (Mant) has been in this situation before.

Mant worked on the OXCHECK study, which found comparable differences of less than 5% between control and intervention groups and in which a strategy identifying patients at high risk was abandoned in favour of targeting those with established disease at yet higher risk.2 It was left to Field et al to show that the OXCHECK study was successful and that the incremental addition of assessment of multiple risk factors to a pre-existing programme targeting smoking and blood pressure was a cost effective way of improving risk factors.3 4

The failure to show substantial differences in outcomes in both Jolly et al's trial and the OXCHECK study has resulted from flaws in the expectations and design of both trials. The trials are based on a prior assumption …