Medication adherence and related determinants in older people with multimorbidity: A cross-sectional study

Abstract

Aim: Identify the medication adherence determinants in older adults with multimorbidity and polypharmacy.

Materials and methods: A cross-sectional study was conducted in a non-probabilistic sample of 245 adults ≥65 years recruited in a general medical ward of one teaching hospital. Data were collected during hospital stay using a face-to-face interview based on a set of validated questionnaires, such as the measure treatment adherence, the beliefs about medicines questionnaire-specific and the geriatric depression scale. Descriptive and multiple linear regression analysis were performed.

Results: Participants' mean age was 78.32 (SD: 6.95) years and 50.6% were women. Older adults lived with an average of 7.51 (SD: 1.95) chronic conditions and had a mean of 7.95 (min. 4; max. 18) medications prescribed. The proportion of older adults adherent to medication was 43.7%. Depression ( $\beta$ = -0.142; p = 0.031), beliefs about treatment necessity ( $\beta$ = 0.306; p = 0.001) and concerns about the medication ( $\beta$ = -0.204; p = 0.001) were found as independent determinants of adherence.

Conclusion: Self-reported medication non-adherence appears to be common in older adults with multimorbidity and polypharmacy. Depression, necessity and concerns should be considered when assessing medication non-adherence in practice. This study will also contribute to develop an intervention to manage adherence in older people, as part of a doctoral research project.

Keywords: behavior determinants; medication adherence; multimorbidity; older adults; polypharmacy.