Challenges to medication adherence with intranasal corticosteroid irrigations.

Abstract

The purpose of this study was to investigate real-world adherence to intranasal corticosteroid irrigations using pharmacy data and assess factors associated with low adherence. Patients undergoing treatment with corticosteroid irrigations for any diagnosis during a 2-year period were prospectively recruited. Subjects completed a one-time set of questionnaires including the Barriers to Care Questionnaire (BCQ), 22-item Sino-Nasal Outcome Test (SNOT-22), and a questionnaire assessing their experience with corticosteroid irrigations. Pharmacy data was used to calculate the medication possession ratio (MPR), a measure of medication adherence graded from 0 to 1. Seventy-one patients were enrolled. Patient diagnoses included chronic rhinosinusitis (CRS) without nasal polyps (n=37), CRS with nasal polyps (n=24), or a non-CRS diagnosis, most commonly chronic rhinitis (n=10). The MPR for the overall group was 0.44±0.33. Just 9.9% of patients had a perfect MPR of 1. Despite low MPR, only 19.7% of patients reported problems taking the medication when directly asked. Lower education resulted in lower MPR (unstandardized B=0.065, p=0.046). Increasing BCQ score, indicating higher barriers to care, was associated with lower MPR (unstandardized B=-0.010, p=0.033). The lower the MPR, the worse the patient SNOT-22 scores (unstandardized B=-15.980, p=0.036). Adherence to corticosteroid irrigations was low and patients underreported issues with their medication. Education and barriers to care were associated with lower adherence, which, in turn, was associated with worse sinonasal quality of life.