Background: Despite the extensive use of process of care measures in pay-for-performance programs, little is known about the effect of improving process performance on patient outcomes.
Methods: Retrospective longitudinal analysis of data extracted from 7228 family practices in the United Kingdom's Quality and Outcomes Framework pay-for-performance program. We estimated the proportion of the change in outcome performance over time which was attributable to change in process performance for 5 chronic conditions (diabetes, coronary heart disease, stroke, epilepsy, and hypertension). Our analytic strategy accounted for bias resulting from unmeasured processes of care and severity of illness.
Results: The estimated improvement in composite outcomes that was attributable to improved process was 29.6% for diabetes, 25.6% for coronary heart disease, 34.7% for stroke, 29.1% for epilepsy, and 17.7% for hypertension. The relationship between processes and outcomes varied little across patient and practice characteristics.
Conclusions: Improvement in process performance in English family practices led to improvements in patient outcomes. Although the effect was modest at the practice-level, process improvements seem to have led to substantial improvements in population health.