Dissertation Title:  "Unintended Consequences: Empirical Studies of Continuity of Care and Financial Incentive Gaming in Primary Care"Strengthening primary care is a priority for health systems globally. Policies intended to modernize primary care can however risk undermining aspects of incumbent delivery models that are essential to cost containment and quality. This dissertation uses data from primary care electronic health records in England to study disruption of continuity of care and gaming responses to financial incentives as two important unintended consequences of recent primary care reforms.

Chapter 1 employs a prospective cohort study design to examine the relationship between continuity of care with a primary care physician and the risks of death and emergency hospitalization for older, medically complex patients. We find relational continuity predicts both mortality and emergency hospitalization risk, with patients at the 75th centile of continuity scores having an 8% lower mortality risk and 7% lower emergency hospitalisation risk than patients at the 25th centile. These findings suggest that payers should consider incentivising the provision of good doctor-patient continuity for older, medically complex patients.

Chapter 2 uses multilevel models to explore longitudinal trends in continuity of care over a decade. We find that continuity has fallen for all patient groups but fastest for older and medically more complex patients. At the practice level, we find that larger practices tend to provide poorer continuity of care. We also find substantial variation between providers in the rates of decline of continuity, not accounted for by observed provider or patient factors. These findings suggest that policies to promote consolidation of primary care providers into larger organizations may have negative consequences for continuity of care. They also point to possible provider-level factors that may be amenable targets for policies to improve continuity of care.

Chapter 3 proposes two novel methods for identifying gaming by clinicians exposed to pay-for-performance incentives. To identify gaming in the management of hypertension, we develop a method for estimating provider rounding behavior when recording blood pressure readings in medical records. We then look for evidence of differential changes in rounding behavior around payment thresholds following incentivization. We also exploit patterns in near threshold retesting for clinical indicators based on blood test results for diabetes and cholesterol control to identify whether providers appear to increase intensity of testing to achieve results within payment thresholds. We find evidence of changes in blood pressure rounding near payment thresholds consistent with gaming behavior, but no differential change in near-threshold retesting for blood test-dependent targets. These findings suggest that it is possible to identify gaming behavior on the intensive margin of care to characterize gaming tendency at the level of individual providers.