Determinants of Nurse Practitioner Use in VA Primary Care Practices

Huang P, Yano EM, Rubenstein LV. Determinants of Nurse Practitioner Use in VA Primary Care Practices. Paper presented at: VA HSR&D National Meeting; 2002 Feb 1; Washington, DC.

Objectives: Since 1996, VHA policy has promoted increased utilization of nurse practitioners (NPs) in primary care (PC) as integral to improving capacity and quality. Little is known about whether this policy has been effective, or what environmental, economic, and organizational factors influence their use. We examined the influence of (1) state laws, (2) economic variables, (3) organizational characteristics, and (4) VHA policy on the utilization of PC NPs. Methods: We surveyed the PC practice leaders of all VA medical centers (VAMC) in 1996 (100% response) and 1999 (94% response) to ascertain the number of PC NPs and characteristics of the practice and parent VAMC. NP practice laws (e.g., prescribing authority) and economic variables (e.g., managed care penetration, NP and physician supply) were assessed using data from previously published studies, the Sourcebook of Health Insurance Data, and HRSA State Health Workforce Profiles. We performed bivariate and multivariate regression modeling of the number of NP FTEEs/10,000 patients in 1999. Results: On average, VAMC PC practices employed 3.49 NPs/10,000 patients in 1996, and 3.47 NPs/10,000 patients in 1999. Higher NP use occurred among urban and western region VAMCs, and in states with greater managed care penetration and NP supply. PC practice characteristics linked to higher NP volume included NP use in 1996, more provider education programs, less reliance on gatekeeping, fewer generalist physicians, and reporting arrangements aligning NPs to PC (instead of Nursing). After multivariate adjustment, the number of PC NPs in 1999 was associated (p < 0.01) with NP volume in 1996, provider education programs, PC alignment of NPs, less gatekeeping, and fewer generalists (all p < 0.01; adjusted R-square 0.23). Conclusions: Despite VHA policies favoring utilization of PC NPs during the past five years, practices are hiring no more NPs now than they were five years ago. Accounting for their numbers in 1996, the number of NPs at a given VAMC PC practice in 1999 is more strongly linked to practice characteristics than to environmental characteristics or VHA policy. Impact statement: State NP practice laws and NP supply are felt to be the primary barriers to full utilization of NPs. However, our results suggest that organizational characteristics may be equally or more important in influencing NP uptake by VA primary care practices.