Methodological issues for population-based research into dementia in developing countries

The 10/66 Dementia Research Group has been formed to promote good-quality, internationally comparable research into dementia in developing countries t hrough active research collaboration. In this position paper, we review exi sting research into dementia prevalence in developing regions of the world. Seven methodologically robust studies were identified. The prevalence of d ementia, age-adjusted to the age structure of the Kerala population, ranged from 1.3 % to 5.3% for all those aged 60 or over and from 1.7% to 5.2% for all those aged 65 and over. Two studies, from Ibadan, Nigeria and Ballabga rh, India, reported strikingly low prevalence figures. The reported prevale nce for most studies was somewhat lower than the consistent figures for Eur ope reported by the EURODEM concerted action. Based on critical review of t he literature, and on the practical research experience of members of the 1 0/66 group, recommendations have been made for procedure in the following a reas: age limits for inclusion in dementia surveys, age ascertainment, samp ling, scope for incidence studies, functional assessment and culture- and e ducation-fair dementia diagnosis. Copyright (C) 2000 John Wiley & Sons, Ltd .