BACKGROUND: Poor adherence contributes to uncontrolled asthma. Pragmatic adherence interventions for primary care settings are lacking.

OBJECTIVE: To test the effectiveness of 2 brief general practitioner (GP)-delivered interventions for improving adherence and asthma control.

METHODS: In a 6-month cluster randomized 2 × 2 factorial controlled trial, with GP as unit of cluster, we compared inhaler reminders and feedback (IRF) and/or personalized adherence discussions (PADs) with active usual care alone; all GPs received action plan and inhaler technique training. GPs enrolled patients prescribed combination controller inhalers, with suboptimal Asthma Control Test (ACT) scores (ACT score ≤19). Inhaler monitors recorded fluticasone propionate/salmeterol adherence (covertly for non-IRF groups) and, in IRF groups, provided twice-daily reminders for missed doses, and adherence feedback. PAD GPs received communication training regarding adherence. Outcomes collected every 2 months included ACT scores (primary outcome) and severe exacerbations. Intention-to-treat mixed-model analysis incorporated cluster effect and repeated measures.

RESULTS: A total of 43 GPs enrolled 143 patients with moderate-severe asthma (mean age, 40.3 ± 15.2 years; ACT score, 14.6 ± 3.8; fluticasone propionate dose, 718 ± 470 μg). Over 6 months, adherence was significantly higher in the IRF group than in non-IRF groups (73% ± 26% vs 46% ± 28% of prescribed daily doses; P < .0001), but not between PAD and non-PAD groups. Asthma control improved overall (mean change in ACT score, 4.5 ± 4.9; P < .0001), with no significant difference among groups (P = .14). Severe exacerbations were experienced by 11% of the patients in IRF groups and 28% of the patients in non-IRF groups (P = .013; after adjustment for exacerbation history; P = .06).

CONCLUSIONS: Inhaler reminders offer an effective strategy for improving adherence in primary care compared with a behavioral intervention or usual care, although this may not be reflected in differences in day-to-day asthma control.