Adherence to controller asthma medications: 6-month prevalence across a US community pharmacy chain.

Abstract

Non-adherence to controller asthma medications is an important public health problem. It is estimated to occur in 30-70% of individuals and is a significant risk factor for asthma morbidity and mortality. The aim of this study was to determine the level of adherence, as indicated by refill rates, to controller asthma medications in a community pharmacy setting. Secondary analyses of a community pharmacy dispensing database in 15 locations throughout Utah. The dispensing records of 2193 patients who received controller medications for asthma in a 12-month period, and had a minimum of 6-month potential coverage (180days) from the date of their first receipt of a controller medication in that period, were examined. Using standard metrics to gauge adherence, the proportion of days covered (PDC) and the medication possession ratio (MPR), the average coverage for controller asthma medications across a 6-month period (180days) was poor, averaging less than 50% of days' availability. Standard cut-offs (≥80% medication availability) indicated that only 14-16% of patients had 'satisfactory' adherence over their 6-month follow-on period. Females and older patients had significantly greater satisfactory adherence. Medication adherence was significantly greater with inhaled corticosteroid (ICS)-long-acting β2 -agonist (LABA) combinations than with ICS alone. This study confirms the considerable scope of the asthma therapy non-adherence problem. Therefore, it is imperative to conduct survey-based research linked directly to pharmacy-based dispensing data to derive patient behavioural, attitudinal and environmental factors that may contribute to the issue, and then pilot and evaluate interventions for change.