The Public Health Impact score: a new measure of public health effectiveness for general practices in England

Background

Health policy in the UK is increasingly focused on the measurement ofoutcomes rather than structures and processes of health care.

Aim

To develop a measure of the effectiveness of primary care in terms ofpopulation health outcomes.

Design and setting

A cross-sectional study of general practices in England.

Method

Twenty clinical quality of care indicators for which there was evidence ofmortality reduction were identified from the national Quality and OutcomesFramework (QOF) pay-for-performance scheme. The number of lives saved by8136 English practices (97.97% of all practices) in 2009/2010 wasestimated, based on their performance on these measures, and a public healthimpact measure, the PHI score, was constructed. Multilevel regression modelswere used to identify practice and population predictors of PHI scores.

Results

The mean estimated PHI score was 258.9 (standard deviation[SD] = 73.3) lives saved per 100 000 registeredpatients, per annum. This represents 75.7% of the maximum potentialPHI score of 340.9 (SD = 91.8). PHI and QOF scores were weaklycorrelated (Pearson r = 0.28). The most powerful predictors of PHIscore were the prevalence of the relevant clinical conditions(β = 0.77) and the proportion ofpatients aged ≥65 years (β = 0.22).General practices that were less successful at achieving their maximumpotential PHI score were those with a lower prevalence of relevantconditions (β = 0.29), larger list sizes(β = −0.16), greater areadeprivation (β = −0.15), and alarger proportion of patients aged ≥65 years(β = −0.13).

Conclusion

The PHI score is a potential alternative metric of practice performance,measuring the estimated mortality reduction in the registered population.Rewards under the QOF pay-for-performance scheme are not closely aligned tothe public health impact of practices.