Ethnic Differences in Persistence with COPD Medications: a Register-Based Study

BACKGROUND: Long-acting bronchodilators (LABDs) are recommended as a first-line maintenance therapy in patients with moderate or severe chronic obstructive pulmonary disease (COPD). The aim of the study was to explore potential ethnic differences in persistence with LABD in COPD patients.

METHODS: A cohort of COPD patients diagnosed in 2003-2007 in Copenhagen, Denmark, was followed for 2 years in the Danish national registers. According to the number of the LABD medications dispensed, individuals were categorized into three therapy groups: monotherapy, drug combination therapy, and multiple drug therapy. Persistence was defined as the period from the first prescription date to the date of discontinuation. Treatment was considered discontinued if the interval between the two prescriptions was longer than the number of days of cumulative medication supply according to defined daily doses plus 7 days.

RESULTS: In total, 1129 incident COPD patients using LABDs were included; 6.7% had other than Danish ethnic background. Survival analyses showed that in the cases where LABD medication combination presented COPD maintenance therapy, ethnic background was associated with the higher risk of the therapy discontinuation: HR = 1.40, 95% CI = 1.03-1.90, p = 0.03. There were no ethnic differences in persistence in the monotherapy or multiple therapy groups.

CONCLUSIONS: COPD patients with other than Danish ethnic background discontinued COPD maintenance therapy more often than ethnic Danes. Attention to the barriers of persistent COPD medication use in COPD patients from ethnic minorities should be payed to facilitate better COPD management.