Defensive Medicine and Physician Behavior

Defensive medicine (DM) concerns physicians undertaking unnecessary procedures out of fear of a medical malpractice lawsuit (positive DM) or avoiding certain patients out of fear of lawsuits (negative DM). Physicians consistently state that their fear of malpractice litigation affects their decisions when interacting with patients. In this research I am interested in understanding the impact of patient conditions on estimates of defensive medicine (DM). I want to understand the impact of tort laws on physician decisions when medical exigencies dictate a c-section. A specific research project in these directions is as follow:

Manuscript in preparation

Chin, S., Zahran, S., & Mushinski, D. Physician Behavior, Tort Reform and Defensive Medicine Revisited: An Investigation of Cesarean Deliveries

We analyze the impact of patient conditions on estimates of defensive medicine (DM). Consistent with theory, we find heterogenous impacts of tort laws across patient conditions. When medical exigencies dictate a c-section, tort laws have no impact on physician decisions. When physicians have latitude in their decision making, we find evidence of DM. When we estimate a model combining all women and not accounting for patient conditions (such as models estimated in previous studies) we obtain a result which is the opposite of DM, which we call offensive medicine (OM). The OM result appears to arise out of a bias in the difference-in-differences estimator associated with changes in the marginal distributions of patient conditions in control and treatment groups. The changes in the marginal distributions appear to arise from the impact of tort law on the market for midwives (substitutes for physicians for low-risk women). Our analysis suggests that not accounting for theoretically expected heterogeneity in physician reactions to changes in tort laws may produce biased estimates of DM.