Family doctor responses to changes in target stringency under financial incentives.

Healthcare providers may game when faced with targets. We examine how family doctors responded to a temporary but substantial increase in the stringency of targets determining payments for controlling blood pressure amongst younger hypertensive patients. We apply difference-in-differences and bunching techniques to data from electronic health records of 107,148 individuals. Doctors did not alter the volume or composition of lists of their hypertension patients. They did increase treatment intensity, including a 1.2 percentage point increase in prescribing antihypertensive medicines. They also undertook more blood pressure measurements. Multiple testing increased by 1.9 percentage points overall and by 8.8 percentage points when first readings failed more stringent target. Exemption of patients from reported performance increased by 0.8 percentage points. Moreover, the proportion of patients recorded as exactly achieving the more stringent target increased by 3.1 percentage points to 16.6%. Family doctors responded as intended and gamed when set more stringent pay-for-performance targets.