title: Sociodemographic, disease, health system, and contextual factors affecting the initiation of biologic agents in rheumatoid arthritis: a longitudinal study.
abstract: OBJECTIVE
  To analyze the effect of sociodemographic, disease, and health system characteristics and contextual features about the community of residence on the subsequent initiation of treatment with biologic agents for rheumatoid arthritis (RA).
  
  
  METHODS
  We analyzed data from the University of California, San Francisco Rheumatoid Arthritis Panel Study for the years 1999-2011. Principal data collection was by a structured annual phone survey. We estimated Kaplan-Meier curves of the time until initiation of biologic agents, stratified by age and income. We also used Cox regression to estimate the effect of individual-level sociodemographic and medical factors, contextual-level socioeconomic status measures, and density of health providers in the local community on the probability of initiating therapy with biologic agents for RA.
  
  
  RESULTS
  In total, 527 persons were included in the panel in 1999, and 229 persons (44%) had initiated therapy with biologic agents by 2011. In multivariable Cox regression models, age <70 years (hazard ratio [HR] for ages 19-54 years 1.89 [95% confidence interval (95% CI) 1.24-2.87] and HR for ages 55-69 years 1.25 [95% CI 0.84-1.87]), Hispanic ethnicity (HR 2.02 [95% CI 1.05-3.86]), household income ≥$30,000/year (HR 1.61 [95% CI 1.12-2.32]), being married or with a partner (HR 1.39 [95% CI 1.00-1.92]), and residence in rural environments (HR 1.96 [95% CI 1.28-2.99]) were associated with a higher probability of initiating biologic agents. Having no (HR 0.18 [95% CI 0.08-0.40]) or only 1-4 rheumatology visits in the year prior to interview (HR 0.60 [95% CI 0.45-0.81]) and living in an area with ≥1 federally qualified health centers (HR 0.63 [95% CI 0.41-0.96]) were associated with a lower probability.
  
  
  CONCLUSIONS
  The probability of initiating therapy with biologic agents is affected by sociodemographic and health system characteristics as well as the nature of the community of residence, resulting in disparities in access to these medications.
authors: University of California, San Francisco.
authors: Edward
authors: E
authors: Yelin
authors: Chris
authors: C
authors: Tonner
authors: Seoyoung C
authors: SC
authors: Kim
authors: Jeffrey N
authors: JN
authors: Katz
authors: John Z
authors: JZ
authors: Ayanian
authors: M Alan
authors: MA
authors: Brookhart
authors: Daniel H
authors: DH
authors: Solomon
mesh_terms: D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000191:economics; D001685:Biological Factors / Q000627:therapeutic use*; D003695:Delivery of Health Care; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012959:Socioeconomic Factors
chemical_list: D018501:Antirheumatic Agents; D001685:Biological Factors