Randomized controlled trial of adherence with single or combination inhaled corticosteroid/long-acting beta-agonist inhaler therapy in asthma.
BACKGROUND
The inhaled corticosteroid (ICS)/long-acting beta-agonist (LABA) combination inhaler has the potential to improve adherence with ICS therapy in asthma.


OBJECTIVE
To determine whether ICS/LABA combination inhaler therapy improves adherence compared with separate inhaler use.


METHODS
In a 24-week randomized controlled parallel group study, 111 subjects were prescribed 125 microg fluticasone dipropionate (FP) and 25 microg salmeterol, 2 actuations twice daily through either a combination inhaler or separate inhalers concurrently. Medication use was recorded by covert electronic monitors. The primary outcome variable was adherence during the final 6-week period, defined as the number of doses taken as a percentage of those prescribed.


RESULTS
Complete adherence data from the final 6-week period were available for 49 and 54 subjects in the separate and combination groups, respectively. The mean (SD) adherence was 73.7% (36.0) for FP, 76.7% (30.5) for salmeterol, and 82.4% (24.5) for FP/salmeterol. There were no significant differences in adherence between FP/salmeterol and FP (-8.7%; 95% CI, -10.6 to 3.3) and salmeterol (-5.6%; 95% CI, -16.4 to 5.1). There was no significant difference in overuse among the FP, salmeterol, or FP/salmeterol groups. In 2 (4%) of 49 subjects, salmeterol was effectively taken as monotherapy during a 6-week period.


CONCLUSIONS
In the setting of a randomized controlled trial, use of a combination ICS/LABA inhaler does not markedly increase adherence above that observed with separate inhaler use. LABA monotherapy was observed in a small proportion of patients prescribed ICS and LABA therapy via separate inhalers.
Perrin
Kyle
K
Medical Research Institute of New Zealand, Wellington, New Zealand.
Williams
Mathew
M
Wijesinghe
Meme
M
James
Kate
K
Weatherall
Mark
M
Beasley
Richard
R
D000280:Administration, Inhalation; D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000627:therapeutic use*; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000627:therapeutic use*; D000328:Adult; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
D000305:Adrenal Cortex Hormones; D000318:Adrenergic beta-Agonists; D018927:Anti-Asthmatic Agents