Dual sensory impairment: Global prevalence, future projections, and its association with cognitive decline.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational epidemiological studies
PubMed 39887563 · doi:10.1002/alz.14465
What was done
Three databases were searched for epidemiological studies investigating the prevalence of dual sensory impairment (comorbid hearing and vision impairment) and its association with cognitive decline. Independent reviewers conducted study selection, data extraction, and risk of bias assessment. Random-effects meta-analyses were used to estimate prevalence, cognitive impairment rates, and odds of incident cognitive decline. Population attributable fraction was calculated, and global projections through 2050 were modeled using United Nations population data.
What was found
Across 43 studies totaling 5,246,796 participants, the pooled prevalence of clinically assessed dual sensory impairment was 5.50% (95% CI: 2.88% to 10.26%), with wide variation by age, region, and ethnicity, and is projected to rise by 27.2% from 2025 to 2050. Among individuals with dual sensory impairment, 59.83% (95% CI: 41.03% to 76.12%) had cognitive impairment. Baseline dual sensory impairment was significantly associated with incident cognitive decline (OR = 1.72, 95% CI: 1.37 to 2.15). Globally, 3.81% (95% CI: 1.05% to 10.55%) of incident cognitive decline was estimated to be attributable to dual sensory impairment.
Why it matters
This meta-analysis provides large-scale benchmark estimates for comorbid vision and hearing loss and quantifies its longitudinal link to cognitive decline, highlighting sensory screening and intervention as potential public health targets.
Limits
The underlying studies were observational, which precludes causal inference between sensory loss and cognitive decline. The prevalence and cognitive impairment estimates exhibited broad confidence intervals, reflecting marked heterogeneity across geographic regions, assessment methods, and demographic cohorts.
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