Concordance of Adherence Measurement Using Self-Reported Adherence Questionnaires and Medication Monitoring Devices: An Updated Review

As medication adherence continues to be a prevalent issue in today's society, the methods used to monitor medication-taking behaviors are constantly being re-evaluated and compared in search of the 'gold standard' measure. Our review aimed to assess the current literature surrounding the correlation between self-reported questionnaires (SRQs) and electronic monitoring devices to determine if these measures produce similar results. We performed a literature search from 2009 to 2017 using PubMed, PubMed In-Process and Non-Indexed, EMBASE, Ovid MEDLINE, and Ovid MEDLINE In-Process. A keyword search using the terms 'patient compliance', 'treatment compliance', 'medication adherence', 'drug monitoring', 'drug therapy', 'electronic', 'digital', 'computer', 'monitor', 'monitoring', 'drug', 'pharmaceutical preparations', 'compliance', and 'medications' was done to capture all articles. We included articles measuring adherence using both monitoring devices and SRQs. Thirty-five articles were included in this review. The average difference in measured adherence rates between the two measures was 9.2% (range -66.3 to 61.5). A majority (62.7%) of articles reported moderate (n = 12; 27.9%), high (n = 5, 11.6%), or significant (n = 10, 23.3%) correlations between SRQs and monitoring devices. Results from our review are consistent with previous studies, as we found that many of our studies produced moderate to high correlation between both SRQs and monitoring devices [Farmer, Clin Ther 21(6):1074-90 (1999), IMS Institute for Healthcare Informatics. Avoidable costs in US health care (2012), Patel et al., Respirology 18(3):546-52 (2013), Siracusa et al., J Cyst Fibros 14(5):621-6 (2015), Smith et al., Int J Cardiol 145(1):122-3 (2010)]. Our findings demonstrate that self-reported adherence produces comparable results to electronic monitoring devices. As there is not yet a 'gold standard' measure for monitoring patient adherence, SRQs and Medication Event Monitoring Systems (MEMS) operating together continue to emerge as the preferred effective method for measuring medication adherence.