Mortality Rates and Mortality Risk Factors in Older Adults with Dementia from Low- and Middle-Income Countries: The 10/66 Dementia Research Group Population-Based Cohort Study

Abstract

Background: Dementia is the main cause of disability in older people living in low- and middle-income countries (LMIC). Monitoring mortality rates and mortality risk factors in people with dementia (PwD) may contribute to improving care provision. Objective: We aimed to estimate mortality rates and mortality predictors in PwD from eight LMICs. Methods: This 3–5-year prospective cohort study involved a sample of 1,488 older people with dementia from eight LMIC. Total, age- and gender-specific mortality rates per 1,000 person-years at risk, as well as the total, age- and gender-adjusted mortality rates were estimated for each country’s sub-sample. Cox’s regressions were used to establish the predictors of mortality. Results: At follow-up, vital status of 1,304 individuals (87.6%) was established, of which 593 (45.5%) were deceased. Mortality rate was higher in China (65.9%) and lower in Mexico (26.9%). Mortality risk was higher in males (HR = 1.57; 95% CI: 1.32,1.87) and increased with age (HR = 1.04; 95% CI: 1.03,1.06). Neuropsychiatric symptoms (HR = 1.03; 95% CI: 1.01,1.05), cognitive decline (HR 1.04; 95% CI: 1.03,1.05), undernutrition (HR = 1.55; 95% CI: 1.19, 2.02), physical impairments (HR = 1.15; 95% CI: 1.03,1.29), and disease severity (HR = 1.43; 95% CI: 1.22,1.63) predicted higher mortality risk. Conclusion: Several factors predicted higher mortality risk in PwD in LMICs. Males, those with higher age, higher severity of neuropsychiatric symptoms, higher number of physical impairments, higher disease severity, lower cognitive performance, and undernutrition had higher mortality risk. Addressing these indicators of long-term adverse outcomes may potentially contribute to improved advanced care planning, reducing the burden of disease in low-resourced settings.