Dementia prevalence in South and Southeast Asia is rising, with modifiable factors in reach

Design

Systematic review and meta-analysis of observational studies

Population

31 studies from South and Southeast Asia; 56,340 people in prevalence analysis

Primary outcome

Prevalence and associated factors of dementia

Effect

Dementia 3.0% (2.0 to 5.0); Alzheimer 2.0%; post-2010 Alzheimer 8.0% (5.0 to 14.0)

This meta-analysis pooled 31 observational studies from South and Southeast Asia, 13 of which (56,340 people) gave prevalence estimates. Overall dementia prevalence was 3.0% (95% CI 2.0% to 5.0%), Alzheimer disease 2.0% and vascular dementia 1.0%, with very high heterogeneity. Alzheimer prevalence in studies after 2010 was 8.0% against 1.0% before 2000. Mean age at onset of Alzheimer disease was about 71.

Older age was strongly associated with Alzheimer disease (OR 3.98). Higher literacy, adequate sleep, periodontal therapy and cognitive stimulation were associated with lower risk. Sex and family history showed no clear association in pooled data.

The rising estimates partly reflect better case-finding, but they match the region's ageing. For Indian practice, the protective factors are the ones clinicians can act on: education and cognitive activity, sleep, and — less often discussed — oral health.

• Ask about memory in older adults at routine visits; dementia is common and under-diagnosed in the region
• Assess sleep and treat sleep disorders in older adults
• Include oral and periodontal health in older adults' preventive care
• Encourage cognitive, social and educational activity at every age
• Use culturally adapted screening tools that do not depend on literacy

Why it matters

It gives regional estimates and modifiable factors relevant to Indian primary and geriatric care.

Don't overread it

Associations with sleep and periodontal therapy are observational, and heterogeneity was extreme; the time trend may reflect better detection.

The statistics, in plain English

I² near 99% means the studies disagreed widely, so the pooled 3% is an average across very different settings, not a figure for any one population.

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