Predictors of Patient-Reported and Pharmacy Refill Measures of Maintenance Inhaler Adherence in Veterans with COPD.

Adherence to COPD inhaled medications was poor as measured by either self-report or pharmacy refill data. There were notable differences in factors associated with adherence based on the method of adherence measurement. Older age, chronic prednisone use, number of prescribed maintenance inhalers, and patient beliefs about medication safety were associated with adherence. Overall, fewer variables were associated with adherence by pharmacy refill. Pharmacy refill and self-report adherence may measure distinct aspects of adherence and be affected by different factors. These results also underscore the importance of addressing patient beliefs when developing interventions to improve medication adherence.