Objectives: This study evaluated adherence to anti-inflammatory controller medication for asthma in a French population.
Methods: This was an observational cohort study that employed data from the health insurance database for the Aquitaine region of France. Eligible subjects were aged between 15 and 45 years and had > or = 1 reimbursement claim for anti-inflammatory controller medication between December 1, 2003, and December 31, 2003. Data were collected from June 1, 2003, to May 28, 2005. New users were defined as those having no reimbursement claim for any asthma controller medication in the 6 months preceding the index date; all others were considered previous users. All subjects were followed for 17 months. Continuous multiple-interval measures of medication availability and medication gaps, treatment persistence, and time to first renewal were calculated for users of inhaled corticosteroids (ICS) alone, users of ICS combined with a long-acting beta2-agonist (LABA) in a single inhaler (ICS/LABA) or in separate inhalers (ICS + LABA), and users of oral leukotriene antagonists.
Results: The study population contained 12,502 new and previous users of anti-inflammatory controller medication for asthma. Their mean (SD) age was 32.0 (8.9) years and 58.3% were female. Previous users had better adherence to treatment than new users with respect to all measures. Adherence was best in previous users of leukotriene antagonists. However, only 40.2% of previous users of leukotriene antagonists had sufficient medication (95% CI, 37.6-42.9), compared with 56.8% of previous users of ICS + LABA (95% CI, 50.7-62.8), 65.5% of previous users of ICS only (95% CI, 63.1-67.9), and 69.8% of previous users of ICS/LABA (95% CI, 68.2-71.4). The rate of persistence over a 1-year period was 44.3% for previous users of leukotriene antagonists (95% CI, 41.7-46.8), compared with 27.1% for previous users of ICS only (95% CI, 25.1-29.1), 32.1% for previous users of ICS/LABA (95% CI, 30.5-33.6), and 44.1% for previous users of ICS + LABA (95% CI, 38.2-50.0).
Conclusion: Adherence to treatment was poor (< or = 44%) in these users of anti-inflammatory controller medications for asthma.