title: Does the Regulatory Environment Affect Nurse Practitioners' Patterns of Practice or Quality of Care in Health Centers?
abstract: To examine the impact of state-granted nurse practitioner (NP) independence on patient-level quality, service utilization, and referrals.
  
  
  
  The National Ambulatory Medical Care Survey's community health center (HC) subsample (2006-2011). Primary analyses included approximately 6,500 patient visits to 350 NPs in 220 HCs.
  
  
  
  Propensity score matching and multivariate regression analysis were used to estimate the impact of state-granted NP independence on each outcome, separately. Estimates were adjusted for sampling weights and NAMCS's complex design.
  
  
  
  Every "NP-patient visit unit" was isolated using practitioner and patient visit codes and, using geographic identifiers, assigned to its state-year and that state-year's level of NP independence based on scope of practice policies. Nine outcomes were specified using ICD-9 codes, standardized drug classification codes, and NAMCS survey items.
  
  
  
  After matching, no statistically significant differences in quality were detected by states' independence status, although NP visits in states with prescriptive independence received more educational services (aIRR 1.66; 95 percent CI 1.09-2.53; p = .02) and medications (aIRR 1.26; 95 percent CI 1.04-1.53; p = .02), and NP visits in states with practice independence had a higher odds of receiving physician referrals (AOR 1.88; 95 percent CI 1.10-3.22; p = .02) than those in restricted states.
  
  
  
  Findings do not support a quality-scope of practice relationship.
authors.affiliation: School of Nursing, The George Washington University, Washington, DC.
authors.forename: Ellen T
authors.initials: ET
authors.lastname: Kurtzman
authors.affiliation: Trachtenberg School of Public Policy and Public Administration, The George Washington University, Washington, DC.
authors.forename: Burt S
authors.initials: BS
authors.lastname: Barnow
authors.affiliation: School of Nursing, The George Washington University, Washington, DC.
authors.forename: Jean E
authors.initials: JE
authors.lastname: Johnson
authors.affiliation: Milken Institute School of Public Health, The George Washington University, Washington, DC.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Simmens
authors.affiliation: Trachtenberg School of Public Policy and Public Administration, The George Washington University, Washington, DC.
authors.forename: Donna Lind
authors.initials: DL
authors.lastname: Infeld
authors.affiliation: Milken Institute School of Public Health and School ofMedicine & Health Sciences, The George Washington University, Washington, DC.
authors.forename: Fitzhugh
authors.initials: F
authors.lastname: Mullan
mesh_terms: D000328:Adult; D003151:Community Health Centers / Q000592:standards* / Q000706:statistics & numerical data; D005260:Female; D019538:Health Care Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D009722:Nurse Practitioners / Q000592:standards* / Q000706:statistics & numerical data*; D057184:Practice Patterns, Nurses' / Q000592:standards* / Q000706:statistics & numerical data; D011320:Primary Health Care / Q000592:standards* / Q000706:statistics & numerical data; D011787:Quality of Health Care / Q000592:standards* / Q000706:statistics & numerical data*; D014481:United States
keywords: Nurse practitioner; community health center; quality of care; scope of practice; state policy