Prevalence of dementia according to DSM-III-R and ICD-10 - Results of the Leipzig Longitudinal Study of the Aged (LEILA75+) Part 1

Background The prevalence of dementia diagnosis according to ICD-10 and DSM -III-R in population surveys remains poorly understood. Aims To report and compare prevalence rates according to DSM-III-R and ICD- 10. Method A population-based sample (n=1692, age 75+ years) was investigated b y a Structured Interview for Diagnosis of Dementia of Alzheimer Type, Multi infarct Dementia and Dementia of other Aetiology according to DSM-III-R and ICD-10 (SIDAM). Results Whereas 17.4% (95% Cl=15.9-19.5) of individuals aged 75+ years suff er from dementia according to DSM-III-R, only 12.4% (95% Cl=10.6-14.2) are diagnosed as having dementia according to ICD-10. The results revealed lowe r ICD-10 rates in all investigated age groups. The largest differences appe ar in the oldest of the elderly. Conclusions The ICD-10 sets a higher threshold for dementia diagnosis. Larg er differences in the eldest age groups might reflect difficulties in apply ing case definitions, especially in those beyond 90 years old. Declaration of interest Supported by Interdisziplinaeres Zentrum fur Klinis che Forschung (IZKF), University of Leipzig (01KS9504, project C7 79934700) .