AbstractFew studies have compared methods of case identification in dementia in detail. In this epidemiological study of cognitive function and dementia, scales and clinical diagnoses were compared in 365 women aged between 70 and 79. The women were interviewed using CAMDEX (Cambridge Examination for Mental Disorders of the Elderly), which includes established and new scales of cognitive function and behaviour. In addition, the information/orientation subscale of the Clifton Assessment Procedure for the Elderly was recorded. The proportions of the population identified by various recommended cutpoints for these scales were calculated. Sensitivities and specificities for these were compared, using CAMDEX clinical diagnosis as the standard. Large differences were found in these according to both the cutpoint set and the level of dementia examined. Each subject was rated by her own general practitioner and a random 10% of the sample was seen using the Geriatric Mental State Examination in addition to CAMDEX. The different diagnoses were compared and considerable variation found.