Antihypertensive medication adherence and associated factors in older adults requiring long-term care: the LIFE Study

BACKGROUND: Consistent antihypertensive treatment reduces cardiovascular risk, but older adults requiring long-term care (LTC) due to functional impairment may have a diminished ability to adhere to treatment. OBJECTIVE: To examine antihypertensive medication adherence among older adults requiring LTC in Japan and to identify its associated factors. DESIGN: Retrospective cohort study. SETTING: 11 municipalities. PARTICIPANTS: Individuals aged ≥65 years requiring LTC and diagnosed with hypertension between April 2016 and March 2020. METHODS: Medical claims data, LTC claims data and LTC certification data were analysed. The study outcome was antihypertensive medication adherence (proportion of days covered >0.8) over 1 year. Using logistic regression analysis, we assessed the associations between adherence and the following factors: care needs levels, paralysis, visual function, hearing function, swallowing function, cognitive function and need for medication intake assistance. RESULTS: The study cohort comprised 69 200 participants (nonadherent: 17 523; 25.3%). At LTC certification application, most participants lived at home (78.3% adherent vs. 64.1% nonadherent). Adherence was negatively associated with high care needs levels (odds ratio: 0.241, 95% confidence interval: 0.222-0.263), bilateral upper limb paralysis (0.605, 0.565-0.648), bilateral lower limb paralysis (0.837, 0.803-0.873), left upper limb paralysis (0.820, 0.746-0.921), moderate visual impairment (0.738, 0.675-0.808), severe hearing impairment (0.683, 0.549-0.853), severe swallowing impairment (0.199, 0.169-0.234), severe cognitive impairment (0.652, 0.621-0.684) and need for full medication intake assistance (0.296, 0.279-0.315). CONCLUSIONS: Over 25% of older adults requiring LTC were nonadherent to antihypertensive treatment. These findings may help to identify high-risk individuals who could benefit from targeted interventions to support medication management.