Is Dementia Differentially Distributed? A Study on the Prevalence of Dementia in Migrant, Urban, Rural, and Tribal Elderly Population of Himalayan Region in Northern India

BACKGROUND: Throughout the world, a large number of surveys have been carried out to find the prevalence of dementia with variable results. AIMS: This study was to generate data on the prevalence of dementia and to generate a hypothesis on the differential distribution across populations. MATERIALS AND METHODS: Four settings identified for the purpose of this study included a migrant, urban, rural, and tribal. The study was conducted in two phases: 1) A screening phase and 2) a clinical phase, on 2,000 individuals above 60 years of age. To complete the required sample of 2,000 elderly individuals, 500 individuals were approached from each site. Nobody refused to participate. RESULTS: A total of 32/2,000 (1.6%) elderly individuals were classified as demented. No case of dementia was reported from tribal population. A look at sex differential reveals that majority (21/32; 66%) of individuals identified as demented were females. As age advanced scores on cognitive screen decreased with elders above 80 years of age showing lowest scores. Out of 32, 18 (56%) of patients classified as demented were more than 80 years of age. CONCLUSION: The findings of this study are in agreement with previous studies which point towards differential distribution of dementia across populations.