title: Sociodemographic and health characteristics, rather than primary care supply, are major drivers of geographic variation in preventable hospitalizations in Australia.
abstract: BACKGROUND
  Geographic rates of preventable hospitalization are used internationally as an indicator of accessibility and quality of primary care. Much research has correlated the indicator with the supply of primary care services, yet multiple other factors may influence these admissions.
  
  
  OBJECTIVE
  To quantify the relative contributions of the supply of general practitioners (GPs) and personal sociodemographic and health characteristics, to geographic variation in preventable hospitalization.
  
  
  METHODS
  Self-reported questionnaire data for 267,091 participants in the 45 and Up Study, Australia, were linked with administrative hospital data to identify preventable hospitalizations. Multilevel Poisson models, with participants clustered in their geographic area of residence, were used to explore factors that explain geographic variation in hospitalization.
  
  
  RESULTS
  GP supply, measured as full-time workload equivalents, was not a significant predictor of preventable hospitalization, and explained only a small amount (2.9%) of the geographic variation in hospitalization rates. Conversely, more than one-third (36.9%) of variation was driven by the sociodemographic composition, health, and behaviors of the population. These personal characteristics explained a greater amount of the variation for chronic conditions (37.5%) than acute (15.5%) or vaccine-preventable conditions (2.4%).
  
  
  CONCLUSIONS
  Personal sociodemographic and health characteristics, rather than GP supply, are major drivers of preventable hospitalization. Their contribution varies according to condition, and if used for performance comparison purposes, geographic rates of preventable hospitalization should be reported according to individual condition or potential pathways for intervention.
authors: *Centre for Health Research, University of Western Sydney, Sydney †The Sax Institute, Sydney, New South Wales ‡Australian National University Medical School, Australian National University, Canberra §Concord Clinical School, University of Sydney, Sydney, New South Wales, Australia ∥Health Economics Research Unit, University of Aberdeen, Aberdeen ¶MRC/CSO Social and Public Health Sciences Unit, University of Glasgow, Glasgow, UK.
authors: Michael O
authors: MO
authors: Falster
authors: Louisa R
authors: LR
authors: Jorm
authors: Kirsty A
authors: KA
authors: Douglas
authors: Fiona M
authors: FM
authors: Blyth
authors: Robert F
authors: RF
authors: Elliott
authors: Alastair H
authors: AH
authors: Leyland
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D005260:Female; D058005:General Practitioners / Q000600:supply & distribution*; D015438:Health Behavior; D006300:Health Services Misuse / Q000706:statistics & numerical data*; D006304:Health Status; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care; D012111:Residence Characteristics; D012737:Sex Factors; D012959:Socioeconomic Factors; D000078329:Workforce