Dementia Prevalence and Risk Factors: Data From Rural Tanzania

Objectives: The burden of dementia is increasing in sub-Saharan Africa (SSA), but there are limited epidemiological data on dementia in SSA. This study investigated the prevalence and associations of dementia in older adults (less than 60 y) attending the outpatient department of Mount Meru Hospital in Tanzania. Methods: This one-phase cross-sectional study screened a sample using the Identification of Dementia in Elderly Africans (IDEA) cognitive screening tool. Those that screened as having possible and probable dementia were further assessed, and diagnosis of dementia was made according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Demographic and risk factor data were collected. Results: Within those screened, 57/1141 (5.0%) (95% CI: 3.7-6.3) had dementia. Female sex [odds ratio (OR)=2.778, 95% CI: 1.074-7.189], having never attended school (OR=6.088, 95% CI: 1.360-27.256), alcohol (U/wk) (OR=1.080, 95% CI: 1.016-1.149), uncorrected visual impairment (OR=4.260, 95% CI: 1.623-11.180), body mass index <18.5 kg/m2(OR=6.588, 95% CI: 2.089-20.775), and stroke (OR=15.790, 95% CI: 3.48-74.475) were found to be significantly, independently associated with dementia. Conclusions: The prevalence of dementia in this population is similar to a recent community-based rate in Tanzania and lower than a hospital-based rate in Senegal. This is the first time the association between visual impairment and dementia has been reported in SSA. Other associations are in keeping with previous literature.