The success of prevention programmes depends to some degree on the extent to which the target population is reached.

GP practice registers for diabetes or hypertension are unaffected by health checks, so are unsuitable for monitoring reach.

Numbers of health checks consistently explain most of the variance in numbers of individuals at high cardiovascular risk.

For every ten health checks, two cases at high cardiovascular risk and a further one with hypertension can be identified.

The number of new cases of hypertension practices identify is the most promising measure of local programme reach.