Domain of practice and the quality of physician performance.

This study has attempted to determine the relationship between physician domain of practice and their quality of medical care. The study examined whether there was a quality difference in practice either 1) between general practitioners and specialists, or 2) between specialists practicing within and outside their specialty domains. The sample consisted of 454 physicians of Hawaii, involving 18 specialty categories: general practitioners (133) and specialists (321). The study finds that when the general practitioners in this study practices without limitation, their quality of care was not as good as that of the specialists. The study also found that when the specialists practiced outside their specialty areas, the relative quality of their performance declined. The latter finding was sustained even when other important practice and background variables were held constant. The study also discusses its generalizability and policy implications.