Intersectional Risks and Adverse Drug Events in Older Adults: A Scoping Review

Introduction
Adverse drug events (ADEs) in older adults contribute to preventable harm, hospitalisation, and health inequalities. While age-related physiological changes affecting drug safety are recognised, less attention is given to how sociodemographic and structural factors such as ethnicity and deprivation jointly shape vulnerability to ADEs. This limits the development of equitable medication safety strategies. This review examines how intersectional risks are conceptualised and analysed in ADE research to inform more inclusive approaches to medication safety.

Method
A scoping review was conducted using JBI methodology and reported in line with PRISMA-ScR guidance. Six databases were searched for peer-reviewed studies (2001–2024) involving community-dwelling adults aged 65 years and older that examined ADEs and analysed at least two sociodemographic or health-related variables. A composite framework was developed combining the National Institute on Aging Health Disparities Framework, the National Institute on Minority Health and Health Disparities Framework, and the Dahlgren and Whitehead model. This framework mapped five domains of influence: biological, behavioural, sociocultural, environmental, and healthcare system.

Results
From 7,900 records, 46 studies met the inclusion criteria. All included biological factors, but fewer examined behavioural (17.0%), sociocultural (19.1%), environmental (31.9%), or healthcare system (25.5%) domains. Eleven studies tested interaction effects or conducted subgroup analyses, and none applied advanced intersectionality-based methods such as Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA) or latent class analysis. Sociodemographic factors were often simplified, for example, using binary ethnicity categories, and mainly treated as confounders rather than explanatory variables. Methodological quality was moderate to high, but equity-related reporting was inconsistent.

Conclusions
Current ADE research does not fully capture the complexity of intersectional risks among older adults. This review identifies a critical evidence gap and provides a framework for equity-informed analysis. Future research should adopt more inclusive, system-aware approaches to medication safety to improve outcomes for older adults facing multiple, overlapping disadvantages.