Nurse practitioner effectiveness: a review of physician-nurse comparison studies.

This article discusses selected conceptual and methodological issues associated with studies evaluating nurse practitioner effectiveness by comparing nurse practitioner and physician practice. The particular areas covered include: the comparison criteria and the standards and the research methods used in these studies. Recommendations for future studies include: (1) activities representing the full range of the nurse practitioner role should be included in any comprehensive evaluation of nurse practitioners; (2) explicit criteria with adequate sensitivity should form the basis of comparisons between nurse practitioners and physicians; (3) empirically established relationships between process and outcome variables should form the basis for establishing nonarbitrary performance standards whenever possible; (4) random sampling of nurse practitioners and physicians should be used when possible. When random sampling is not possible, providers should be selected using variables known to correlate with quality of care; (5) random assignment of patients to providers is strongly recommended, taking care to use clients new to both providers; (6) use of multiple data sources is recommended to decrease the current heavy reliance on adults; (7) conclusions should point out differential findings identifying those which favor physicians, those which favor nurse practitioners, and those identifying no differences between providers.