Andrew R Sommers1, Douglas R Wholey. 1. Center for Outcome and Effectiveness Research, Agency for Healthcare Research and Quality, Rockville, MD, USA. asommers@rti.org
Abstract
OBJECTIVES: To examine the effects of HMO enrollment and HMO competition on evaluations of physician thoroughness through their effects on gatekeeping and having a usual source of care and to determine whether the effects of HMO competition spill over to individuals not enrolled in HMOs and whether these effects differ in those enrolled vs not enrolled in HMOs. STUDY SAMPLE: A nationally representative sample of 27 441 adults from the household component of the Community Tracking Study-Round 1 (July, 1996, through July, 1997). STUDY DESIGN: A retrospective econometric analysis of Community Tracking Study data merged with measures of HMO competition. METHODS: Gatekeeping was regressed on HMO enrollment, HMO competition, and control variables using ordered logistic regression. Usual source of care was regressed on gatekeeping, HMO enrollment, HMO competition, and control variables using logistic regression. Evaluation of physician thoroughness was regressed on gatekeeping, usual source of care, HMO enrollment, HMO competition, and control variables using multivariate regression. RESULTS: HMO competition increases use of gatekeeping and gatekeeping increases having a usual source of care for all individuals. For HMO enrollees, HMO competition increases having a usual source of care, whereas for those not in HMOs, it decreases having a usual source of care. For all individuals, having a usual source of care increases evaluation of physician thoroughness. For those in HMOs, gatekeeping decreases evaluation of physician thoroughness. CONCLUSIONS: For HMO enrollees, the overall effect of HMO competition is to increase evaluations of physician thoroughness. For those not in HMOs, although there are HMO competition spillover effects, they are offsetting, resulting in no overall effect of HMO competition on evaluations of physician thoroughness.
OBJECTIVES: To examine the effects of HMO enrollment and HMO competition on evaluations of physician thoroughness through their effects on gatekeeping and having a usual source of care and to determine whether the effects of HMO competition spill over to individuals not enrolled in HMOs and whether these effects differ in those enrolled vs not enrolled in HMOs. STUDY SAMPLE: A nationally representative sample of 27 441 adults from the household component of the Community Tracking Study-Round 1 (July, 1996, through July, 1997). STUDY DESIGN: A retrospective econometric analysis of Community Tracking Study data merged with measures of HMO competition. METHODS: Gatekeeping was regressed on HMO enrollment, HMO competition, and control variables using ordered logistic regression. Usual source of care was regressed on gatekeeping, HMO enrollment, HMO competition, and control variables using logistic regression. Evaluation of physician thoroughness was regressed on gatekeeping, usual source of care, HMO enrollment, HMO competition, and control variables using multivariate regression. RESULTS: HMO competition increases use of gatekeeping and gatekeeping increases having a usual source of care for all individuals. For HMO enrollees, HMO competition increases having a usual source of care, whereas for those not in HMOs, it decreases having a usual source of care. For all individuals, having a usual source of care increases evaluation of physician thoroughness. For those in HMOs, gatekeeping decreases evaluation of physician thoroughness. CONCLUSIONS: For HMO enrollees, the overall effect of HMO competition is to increase evaluations of physician thoroughness. For those not in HMOs, although there are HMO competition spillover effects, they are offsetting, resulting in no overall effect of HMO competition on evaluations of physician thoroughness.
Authors: Amanda S Gilmore; Yingxu Zhao; Ning Kang; Kira L Ryskina; Antonio P Legorreta; Deborah A Taira; Richard S Chung Journal: Health Serv Res Date: 2007-12 Impact factor: 3.402