The INCA (Inhaler Compliance Aid) – validation against established measures of adherence

Abstract

Background Despite evidence for long-acting inhaled therapy, non-adherence in COPD is common, resulting in higher exacerbation rates, increased mortality and poorer quality-of-life. The Inhaler Compliance AidTM (INCA) is a novel device that records both when and how medication is inhaled by using an electronic acoustic recording. This study aimed to validate the INCA device against established adherence measures (self-report and prescription refill) and establish predictive validity for health outcomes. Method COPD patients consented to use a salmeterol/fluticasone inhaler fitted with INCA device, and completed baseline and 1-month measures of self-reported adherence (Morisky Medication Adherence Scale; MMAS), assessment of quality-of-life (St Georges Respiratory Questionnaire) and health status (COPD Assessment Test). This project established concurrent validity of the INCATM device by correlating self-reported adherence (Morisky Medication Adherence Scale; MMAS) and prescription refill data (national pharmacy claims records 1-year prior to study enrolment) with attempted and actual adherence (INCA). Results Preliminary analysis (n=75, 48% female, mean age=69 (±9.9)) showed a correlation between attempted adherence (INCA) and self-reported adherence (MMAS) (r=.35, p<0.001), and a correlation between actual adherence (INCA) and self-reported adherence (MMAS) (r=.56, p<0.001). Study recruitment is ongoing, and future work will establish predictive validity of INCA, and the correlation of attempted and actual adherence (INCA TM) with adherence measured by prescription refill. Discussion The study findings suggest that the INCA device is a valid measure of adherence. The INCA is a unique device that has potential to become a gold-standard adherence measure for respiratory diseases.