[Epidemiological study on cognitive abilities in the elderly in two separate rural areas in Iceland.]

This study was undertaken to estimate the cognitive abilities in an elderly population in rural areas in Iceland and to get an idea of the prevalence of dementia. By examining inhabitants in two different areas it was further possible to detect any possible difference in these areas.

All persons aged 70 and over, living independently in the community and in institutions in two geographically separate areas were contacted. The areas were an agricultural (area A) and a fishing (area F) one. Four simple neuropsychological tests where used, the MMSE (Mini Mental State Examination), WAIS (Wechsler Adult Intelligence Scale)-Similarities, Trail making test A and Trail making test B. Two students in psychology and a teacher were trained in applying the tests but the results were scored and interpreted by the authors.

In area A, 280 of 353 (79.3%) participated and in area F, 190 of 238 (79.8%). Participation was thus similar in both areas. There was a highly significant difference in all the tests with p<0.01 in Trail making test B but p<0.001 in the other three tests. In all the tests the results were better among the population in area A. The prevalence of dementia as estimated by the MMSE showed a prevalence of 14.4% in area A and 35.7% in area F.

A significant difference in cognitive abilities was found between the elderly inhabitants of two separate rural areas in Iceland. There is substantial evidence to suggest that this difference is real but it is however not clear if the prevalence of dementia is higher in this study than in others. It is postulated that the difference found is due to cultural differences.