Associations Between Polypharmacy and Cognitive and Physical Capability: A British Birth Cohort Study

Abstract

ObjectivesTo investigate longitudinal associations between polypharmacy and cognitive and physical capability and to determine whether these associations differ with cumulative exposure to polypharmacy.DesignProspective birth cohort study.SettingEngland, Scotland, and Wales.ParticipantsAn eligible sample of men and women from the Medical Research Council National Survey of Health and Development with medication data at age 69 (N=2,122, 79%).MeasurementsCognitive capability was assessed using a word learning test, visual search speed task, and the Addenbrooke's Cognitive Examination, Third Edition (ACE‐III). Physical capability was measured using chair rise speed, standing balance time, walking speed, and grip strength.ResultsPolypharmacy (5–8 prescribed medications) was present in 18.2% of participants at age 69 and excessive polypharmacy (≥9 prescribed medications) in 4.7%. Both were associated with poorer cognitive and physical capability in models adjusted for sex, education, and disease burden. Stronger associations were found for excessive polypharmacy (e.g., difference in mean ACE‐III scores comparing polypharmacy=−2.0, 95% CI=−2.8 to −1.1 and excessive polypharmacy=−2.9, 95% CI=−4.4 to −1.4 with no polypharmacy). Participants with polypharmacy at age 60 to 64 and at age 69 showed stronger Negative associations with cognitive and physical capability were stronger still in participants with polypharmacy at both age 60 to 64 and at age 69 (e.g. difference in mean chair rise speed, comparing polypharmacy with no polypharmacy at both ages=−3.9, 95% CI=−5.2 to −2.6 and at age 60–64 only=−2.5, 95% CI=−4.1 to −0.9).ConclusionPolypharmacy at age 60 to 64 and age 69 was associated with poorer physical and cognitive capability, even after adjusting for disease burden. Stronger negative associations were seen in participants with longstanding polypharmacy, suggesting a cumulative, dose‐dependent relationship (where dose is the number of prescribed medications). Future research aiming to improve cognitive and physical capability should consider interventions to reduce the duration and level of polypharmacy at younger ages, in addition to optimizing disease control with appropriate medications.

How Chronic Is Polypharmacy in Old Age? A Longitudinal Nationwide Cohort Study

“…The main strength of this study is that it includes the entire population of older adults aged 65 years or older with polypharmacy in Sweden, followed up for 3 years. The monthly assessments of polypharmacy exposure provide better time resolution of the fluctuations in polypharmacy status than earlier survey‐based studies with longer time periods between survey waves . There are some notable limitations to the study.…”

“…Polypharmacy may not always be a chronic and persistent hazard, making it difficult to provide tailored interventions at the right time for older adults . Third, observational studies aiming at establishing a causal association between polypharmacy and subsequent health outcomes have seldom considered polypharmacy as a time‐varying or cumulative exposure based on the assumption that polypharmacy is by definition chronic . Yet, until now, this assumption has remained untested and there exists no consensual definition of what constitutes chronic polypharmacy .…”

Willingness to Change Medications Linked to Increased Fall Risk: A Comparison between Age Groups

“…Older adults were more likely to report using a higher number of medications compared with adults ages 55 to 64. Previous studies showed polypharmacy was independently associated with a significant decline in cognitive and physical capability and increased risk of falls (14% increase in fall risk with the each medication added beyond four medications) . Therefore, targeting older adults for tapering unnecessary medication has potential health benefits.…”

A holistic approach to healthy ageing: how can people live longer, healthier lives?

“…This figure is significantly greater in those with dementia and other chronic conditions. Future research should consider the additional impact of polypharmacy on the ageing process (107,108) . 2 The impact of generational resilience: Many of the cohort studies incorporate the postwar generation.…”