title: Socioeconomic gradients in tiotropium use among adults with COPD.
abstract: BACKGROUND
  Inequalities in the use of new medications may contribute to health disparities. We analyzed socioeconomic gradients in the use of tiotropium for chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  In a cohort of adults with COPD aged > or = 55 years identified through population-based sampling, we elicited questionnaire responses on demographics, socioeconomic status (SES; lower SES defined as high school education or less or annual household income < US $20,000), and medication use and other clinical variables. In a subset we obtained pulmonary function testing. We used multiple logistic regression analysis to estimate the associations between SES and tiotropium use in COPD, adjusting for disease severity measured by a COPD Severity Score.
  
  
  RESULTS
  Of 427 subjects, 44 (10.3%) reported using tiotropium in 2006. Adjusting for COPD severity, lower SES was associated with reduced odds of tiotropium use (OR 0.3; 95% CI 0.1-0.7; p = 0.005). Among the subset with lung function data (n = 95), after including COPD Global Obstructive Lung Disease (GOLD) Stage > or = 2 in the model, lower SES remained associated with reduced odds oftiotropium use (OR 0.03; 95% CI < 0.001-0.7; p = 0.03). Including forced expiratory volume in one second in the model as a continuous variable instead of GOLD Stage > or = 2 yielded similar results for lower SES (OR 0.1; 95% CI < 0.001-0.5; p = 0.02).
  
  
  CONCLUSIONS
  There was a strong SES gradient in tiotropium use such that there was less use with lower SES. To the extent that this is an efficacious medication for COPD, this gradient represents a potential source of health disparities.
authors.affiliation: Division of Occupational and Environmental Medicine, Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94143-0924, USA. paul.blanc@ucsf.edu
authors.forename: Paul D
authors.initials: PD
authors.lastname: Blanc
authors.forename: Mark D
authors.initials: MD
authors.lastname: Eisner
authors.forename: Edward H
authors.initials: EH
authors.lastname: Yelin
authors.forename: Gillian
authors.initials: G
authors.lastname: Earnest
authors.forename: John R
authors.initials: JR
authors.lastname: Balmes
authors.forename: Steven E
authors.initials: SE
authors.lastname: Gregorich
authors.forename: Patricia P
authors.initials: PP
authors.lastname: Katz
mesh_terms: D000328:Adult; D000368:Aged; D018680:Cholinergic Antagonists / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D054624:Health Status Disparities; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000191:economics; D012129:Respiratory Function Tests; D012602:Scopolamine Derivatives / Q000627:therapeutic use*; D012720:Severity of Illness Index; D012923:Social Class; D013147:Spirometry; D000069447:Tiotropium Bromide; D014481:United States
chemical_list: D018680:Cholinergic Antagonists; D012602:Scopolamine Derivatives; D000069447:Tiotropium Bromide