Effects of physician supply on early detection of breast cancer.

Background: There are few studies examining the effects of physician supply on health-related outcomes. We hypothesized that increasing physician supply and, in particular, increasing primary care supply would be related to earlier detection of breast cancer.

Methods: Information on incident cases of breast cancer occurring in Florida in 1994 (n = 11,740) was collected from the state cancer registry. Measures of physician supply were obtained from the 1994 AMA Physician Masterfile. The effects of physician supply on the odds of late-stage diagnosis were examined using multiple logistic regression.

Results: There was no relation between overall physician supply and stage of breast cancer of diagnosis. Each 10th percentile increase in primary care physician supply, however, resulted in a 4% increase in the odds of early-stage diagnosis (adjusted odds ratio = 1.04, 95% confidence interval = 1.01-1.06).

Conclusions: The supply of primary care physicians was significantly associated with earlier stage of breast cancer at diagnosis. This study suggests that an appropriate balance of primary care and specialty physician supply might be an important predictor of health outcomes.