Socioeconomic gradients in tiotropium use among adults with COPD.
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.
Blanc
Paul D
PD
Division of Occupational and Environmental Medicine, Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94143-0924, USA. paul.blanc@ucsf.edu
Eisner
Mark D
MD
Yelin
Edward H
EH
Earnest
Gillian
G
Balmes
John R
JR
Gregorich
Steven E
SE
Katz
Patricia P
PP
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
D018680:Cholinergic Antagonists; D012602:Scopolamine Derivatives; D000069447:Tiotropium Bromide