Association of disability and 12-year all-cause and cause-specific mortality: analyses from the Wellbeing of Older People cohort study in Uganda

TL;DR

Severe disability is strongly linked to higher mortality in older adults in Uganda, highlighting the need for better healthcare access and support.

Contribution

This study provides new evidence on the strong association between disability and mortality in sub-Saharan Africa.

Findings

Severe disability was associated with a 3.88-fold higher mortality risk compared to none/mild disability.

The mortality risk remained elevated even after adjusting for sociodemographic and health factors.

Disability was linked to higher risks for HIV, non-communicable diseases, and indeterminate causes of death.

Abstract

Disability is linked to poor health outcomes and increased mortality, yet evidence on this relationship in sub-Saharan Africa is limited. This study investigated the association between disability and all-cause and cause-specific mortality among older adults in Uganda.

The analysis was based on longitudinal data from the Wellbeing of Older People Study, an open cohort of individuals aged at least 50 years and followed over five data collection waves from 2009 to 2022. Disability was assessed using the WHO Disability Assessment Schedule 2.0. Mortality data were collected, supplemented by verbal autopsies. Gompertz regression models examined the association between disability severity and mortality, adjusting for sociodemographic, socioeconomic, health access and health risk factors.

Among 938 participants followed up for a median of 8.0 years (interquartile range (IQR): 3.2–11.5), 153 deaths were recorded (mortality rate: 2.4 per 100 person-years). The age-sex-adjusted analyses showed that the hazard ratio (HR) was 3.88-fold higher (95% confidence interval (CI) 2.50 to 6.02; p value <0.001) among people with severe disability compared with none/mild disability. Adjusting for sociodemographic, economic, social support and health factors (health status, access and risk factors) somewhat attenuated the association (adjusted HR (aHR) 3.08, 95% CI 1.92 to 4.93; p value <0.001). This excess risk persisted across broadly categorised causes of death: HIV (aHR 8.96, 95% CI 2.52 to 31.83), communicable diseases excluding HIV (aHR 2.24, 95% CI 0.80 to 6.25), non-communicable diseases (aHR 2.29, 95% CI: 1.20 to 4.37) and indeterminate causes of death (aHR 6.89, 95% CI 1.63 to 29.1). Additionally, disability was associated with sociodemographic disadvantages, poor healthcare access and higher prevalence of health risk factors.

Severe disability was strongly associated with elevated mortality risk among older Ugandans, underscoring the need for targeted interventions to improve health equity. Reducing mortality disparities might require addressing barriers to healthcare access, stronger social support and integrating disability-inclusive policies in achieving global health targets, including Universal Health Coverage.