title: Factors associated with higher healthcare costs in individuals living with arthritis: evidence from the quantile regression approach.
abstract: OBJECTIVE
  To examine the factors associated with higher healthcare cost in women with arthritis, using generalized linear models (GLMs) and quantile regression (QR).
  
  
  METHODS
  This is a cross-sectional healthcare cost study of individuals with arthritis that focused on older Australian women. Cost data were drawn from the Medicare Australia datasets.
  
  
  RESULTS
  GLM results show that healthcare cost was significantly associated with various socio-demographic and health factors. Although QR analysis results show the same direction of association between these factors and healthcare cost as in the GLMs, they indicate progressively increased effect sizes at the 50th, 75th, 90th and 95th percentiles.
  
  
  CONCLUSIONS
  Findings suggest traditional regression models such as GLMs that assume a single rate of change to accurately describe the relationships between explanatory variables and healthcare costs across the entire distribution of cost can produce biased results. QR should be considered in future healthcare cost research.
authors.affiliation: a 1 Research Centre for Gender, Health & Ageing, The University of Newcastle, HMRI Building, C/- University Drive, Callaghan, NSW 2308, Australia.
authors.forename: T K T
authors.initials: TK
authors.lastname: Lo
authors.affiliation: b 2 Human Health and Social Sciences/Higher Education Division, Central Queensland University, Bruce Highway, Rockhampton Qld 4702, Australia.
authors.forename: Lynne
authors.initials: L
authors.lastname: Parkinson
authors.affiliation: c 3 The University of Sydney, Charles Perkins Centre, Research and Education Hub, The University of Sydney, NSW 2006, Australia.
authors.forename: Michelle
authors.initials: M
authors.lastname: Cunich
authors.affiliation: a 1 Research Centre for Gender, Health & Ageing, The University of Newcastle, HMRI Building, C/- University Drive, Callaghan, NSW 2308, Australia.
authors.forename: Julie
authors.initials: J
authors.lastname: Byles
mesh_terms: D000369:Aged, 80 and over; D001168:Arthritis / Q000191:economics / Q000628:therapy*; D001315:Australia; D003430:Cross-Sectional Studies; D005260:Female; D017048:Health Care Costs; D006801:Humans; D016014:Linear Models; D012044:Regression Analysis
keywords: Australia; arthritis; claims database; economic burden; healthcare costs; patient-reported outcomes