Abstract
Introduction and objectives: Adherence to medication regimen is commonly assessed through questionnaires, some of which are validated via self-administration. The inadequate health literacy of elderly people pushes researchers to the use of interviews as a method of administration. The aims of this study were to compare the results obtained with an interviewer-administered and a self-administered medication adherence questionnaire and to evaluate the consequences of the adherence status classification of individuals. Methods: A cross-sectional study was performed in which the Medida de Adesão aos Tratamentos adherence questionnaire was administered to adult patients who were taking at least 1 antihypertensive drug. The data were collected in 7 community pharmacies in central Portugal between March 2014 and September 2015 in 2 different phases: in the first phase, the questionnaire was applied during a healthcare professional interview, and the second phase involved a self-report administration. A confirmatory factor analysis was conducted, and the measurement and structural invariances across the application methods were examined. Results: A sample of 425 patients with a mean age of 68.21 ± 10.56 years participated in the study. The confirmatory factor analysis revealed that both the interview and self-report had a good fit with the original model, although the self-report results exhibited a better fit. In the interview administration, we obtained lower values for skewness and higher levels of kurtosis. The patients subjected to the interview administration presented with a 9.7% higher tendency to answer “never” when compared with the self-administered application, which overestimated adherence. Conclusions: The interview administration method induced bias that led to a higher percentage of “never” answers and a subsequent overestimation of adherence levels. Self-report administration should be preferred in the application of medication adherence questionnaires.
Original language | English |
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Pages (from-to) | 1252-1257 |
Number of pages | 6 |
Journal | Journal of Evaluation in Clinical Practice |
Volume | 23 |
Issue number | 6 |
DOIs | |
Publication status | Published - Dec 2017 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2017 John Wiley & Sons, Ltd.
Keywords
- bias (epidemiology)
- medication adherence
- patient outcome assessment
- patient preference
- reproducibility of results
- surveys and questionnaires