Impact of Pay for Performance on Ethnic Disparities in Intermediate Outcomes for Diabetes: A Longitudinal Study

OBJECTIVE - The purpose of this study was to examine the impact of a major pay for performance incentive on trends in the quality of diabetes care in white, black, and South Asian ethnic groups in an urban setting in the U.K. RESEARCH DESIGN AND METHODS - We developed longitudinal models examining the quality of diabetes care in a cohort of ethnically diverse patients in Southwest London using electronic family practice records. Outcome measures were mean blood pressure and AlC values between 2000 and 2005. RESULTS - The introduction of pay for performance was associated with reductions in mean systolic and diastolic blood pressure, which were significantly greater than those predicted by the underlying trend in the white (-5.8 and -4.2 mmHg), black (-2.5 and -2.4 mmHg), and South Asian (-5.5 and -3.3 mmHg) groups. Reductions in AlC levels were significantly greater than those predicted by the underlying trend in the white group (-0.5%) but not in the black (-0.3%) or South Asian (-0.4%) groups. Ethnic group disparities in annual measurement of blood pressure and AlC were abolished before the introduction of pay for performance. CONCLUSIONS - The introduction of a pay for performance incentive in U.K. primary care was associated with improvements in the intermediate outcomes of diabetes care for all ethnic groups. However, the magnitude of improvement appeared to differ between ethnic groups, thus potentially widening existing disparities in care. Policy makers should consider the potential impacts of pay for performance incentives on health disparities when designing and evaluating such programs.