title: The effect of distance to primary care physician on health care utilization and disease burden.
abstract: BACKGROUND
  The relationship of distance to care with total health care utilization and disease burden is not well understood among the managed care population.
  
  
  OBJECTIVE
  The aim of this study was to examine the relationship between the distance from a patient's home to his or her primary care physician (PCP) and the patient's health characteristics.
  
  
  METHODS
  This was a population-based study of commercial health maintenance organization (HMO) members enrolled in one medium-sized health plan in Michigan in 2001. This study measured health care utilization from all settings (per member per year [PMPY]). Disease burden measure was based on the Adjusted Clinical Group (ACG) system. Distance was defined as straight-line distance between a member's residency and his or her PCP. Both direct standardization and regression modeling were used to assess the effect of distance on utilization.
  
  
  RESULTS
  Both utilization and disease burden increased as distance increased, especially among members selecting PCPs in an academic health system (AHS). The difference in observed utilization between local (0-10 miles) and distant (>30 miles) members was 973 dollars (PMPY) for the AHS and 193 dollars (PMPY) for the community independent practice associations (IPA). Compared with age-sex adjustment, ACG adjustment reduced local-distant difference within the same practice group to a greater extent (281 dollars and 59 dollars remaining for the academic and community groups, respectively). Distance as a whole exerted a statistically significant positive effect on either disease burden score or utilization in regression modeling.
  
  
  CONCLUSIONS
  HMO members consume more health care and had higher disease burden as their distance from their PCPs increased. The distance traveled by the individuals to their PCPs could be incorporated when adjusting managed care financial risk models. Other remedies include negotiating higher capitation rates for distant patients, carving out distant patients from any financial risk model, or excluding such patients from provider performance assessment.
authors.affiliation: University of Michigan Medical School, Ann Arbor, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Billi
authors.forename: Chih-Wen
authors.initials: CW
authors.lastname: Pai
authors.forename: David A
authors.initials: DA
authors.lastname: Spahlinger
mesh_terms: D017281:Cost of Illness; D005260:Female; D019538:Health Care Surveys; D006296:Health Services / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D011320:Primary Health Care; D014195:Travel; D014481:United States