The psychogeriatric assessment scales (PAS): further data on psychometric properties and validity from a longitudinal study of the elderly.

The PAS is a standardized interview which assesses the changes seen in dementia and depression using a set of scales. There are three scales derived from an interview with the subject (cognitive impairment, depression, stroke) and three from an interview with an informant (cognitive decline, behaviour change, stroke). The aim was to provide data on the psychometric properties and validity of the PAS. The scales were originally developed using data from the first wave of a longitudinal study of the elderly. Reported here are further data on the PAS from the second wave of the same study, carried out 3 1/2 years later. The setting was a community survey carried out in the Australian city of Canberra. Seven hundred and nine elderly persons, with a mean age of 80 years, and 641 informants participated. Besides the PAS, participants were administered several other scales: the Mini-Mental State Examination, the Informant Questionnaire on Cognitive Decline in the Elderly, the National Adult Reading Test and the Goldberg anxiety and depression scales. Diagnoses of dementia and depression were made with the Canberra Interview for the Elderly, from which the PAS is derived. Confirmatory factor analysis replicated the five-factor model which underpins the PAS. The PAS was found to correlate with the other scales having similar content and showed correspondence with diagnoses of dementia and depression derived from the Canberra Interview for the Elderly. Longitudinal data supported the validity of the cognitive decline scale as a measure of change. Overall, the results support the original psychometric and validity research on the PAS.