Duke 2008 | ASHE | Equity and Efficiency in Health and Healthcare

This paper investigates the effect of switching primary care physicians on the health of older patients. Previous literature suggests that longer-standing physician-patient relationships foster less expensive, less intensive care through decreased likelihood of hospitalization and better use of selected preventative services. However, these studies fail to take into account the potential endogeneity of switching behavior. Patients may be prompted to switch doctors by a decline in health, and the perception that their current doctor is not meeting a sufficient standard of care. Thus, causality could go in either direction if interruptions in care are associated with worse health outcomes and higher costs.

We use Medicare claims records for the years 1985-1995 to obtain patients' probabilities of switching doctors, then examine whether the probability of switching doctors affects the probability of survival and preventable illness. To remove the potential endogeneity of switching, we use as an instrument the retirement or out-of-state move of the patient's primary care doctor. This is unlikely to be correlated with the patient's characteristics, but will lead to an interruption in care. We expect that interruptions in care ( i.e. greater probability of switching) will lead to a lower probability of survival at a given age and to a higher probability of preventable illness. We make a back-of-the-envelope calculation for the value of continuing the patient-physician relationship, conditional on the length of the relationship thus far.