Missing in action: Care by physician assistants and nurse practitioners in national health surveys

Objective. To assess applicability of national health survey data for generalizable research on outpatient care by physician assistants (PAs) and nurse practitioners (NPs). Data Sources. Methodology descriptions and 2003 data files from the National Ambulatory Medical Care Survey, the National Hospital Ambulatory Medical Care Survey, the Medical Expenditure Panel Survey, and the Community Tracking Study. Study Design. Surveys were assessed for utility for research on PA and NP patient care, with respect to survey coverage, structure, content, generalizability to the U.S. population, and validity. National estimates of patient encounters, statistically adjusted for survey design and nonresponse, were compared across surveys. Data Collection/Extraction Methods. Surveys were identified through literature review, selected according to inclusion criteria, and analyzed based on methodology descriptions. Quantitative analyses used publicly available data downloaded from survey websites. Principal Findings. Surveys varied with respect to applicability to PA and NP care. Features limiting applicability included (1) sampling schemes that inconsistently capture nonphysician practice, (2) inaccurate identification of provider type, and (3) data structure that does not support analysis of team practice. Conclusions. Researchers using national health care surveys to analyze PA and NP patient interactions should account for design features that may differentially affect nonphysician data. Workforce research that includes NPs and PAs is needed for national planning efforts, and this research will require improved survey methodologies.