https://orcid.org/0000-0001-7181-0981
Abstract
Background
Self-report measures are important tools for assessing adherence to medication. Many of these scales, however, combine the extent of and reasons for nonadherence in one instrument, and have limited reliability and validity. The present study was the first to assess the convergent validity of the self-reported Domains of Subjective Extent of Nonadherence (DOSE-Nonadherence) scale with electronically measured adherence to a single cardiovascular medication.
Methods
English- and Spanish-speaking patients evaluated for acute coronary syndrome (N=165; n=68 and n= 97, respectively) were recruited from an urban academic emergency department. Post-hospital discharge, participants were mailed a medication bottle with an electronic cap (eCAP) that recorded bottle openings. At 1 month, participants completed the 3-item DOSE-Nonadherence scale, which assessed the extent to which patients missed, skipped, or did not take the eCAP-monitored medication over the past 7 days. Correlations, sensitivity, and specificity were calculated using eCAP-monitored correct dosing adherence over the same 7-day time period as the reference standard.
Results
The most commonly assessed medication was aspirin (70.91%). Correlations between self-reported and electronically monitored adherence were low-to-moderate: English-speaking participants (n=68), r=0.24, p=0.046; Spanish-speaking participants (n=97), r=0.18, p=0.071. Sensitivity was low (0.47 English, 0.28 Spanish) and specificity was moderate (0.77 English, 0.88 Spanish).
Conclusions
The DOSE-Nonadherence scale was associated with electronically monitored adherence to a single daily cardiovascular medication in English-speaking participants, but had weak diagnostic properties when using electronic adherence as the reference standard.
Acknowledgments
This work was supported by the National Heart, Lung, and Blood Institute (NHLBI; R01HL117832, and R01HL123368). The content is solely the responsibility of the authors and does not necessarily represent the official view of the National Institutes of Health. The funding body had no role in the design of the study, collection and interpretation of data, or in writing this manuscript. Effort on this manuscript was also made possible by a Research Career Scientist award from the Health Services Research and Development service of the Department of Veterans Affairs (VA; grant number RCS 14-443). The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the VA or the United States Government.
Disclosure
Dr Ian Kronish reports grants from NHLBI. Dr Corrine Voils reports grants from Health Services Research and Development Service of the Department of VA during the conduct of the study. The authors report no other conflicts of interest in this work.