The cognitive decline scale of the psychogeriatric assessment scales (PAS): longitudinal data on its validity

Objective. The Cognitive Decline scale of the Psychogeriatric Assessment Sc ales (PAS)(1) uses informant data to assess retrospectively change from ear lier in life. Data from a 7-8-year longitudinal study were used to assess t he validity of this scale against changes in cognitive performance and mort ality. Design and measures. PAS data were collected on three occasions, with gaps of 3.6 and 4.1 years between the waves. The Cognitive Decline score at Wave 3 was validated retrospectively against actual change on a brief test of c urrent cognitive status (the PAS Cognitive Impairment scale) over the three waves, while the Cognitive Decline score at Wave I was assessed for predic tive validity against future mortality and cognitive change. Setting. A community survey in the Australian cities of Canberra and Queanb eyan. Participants. Participants were aged 70+ at the beginning of the study. The sample size varied from 729 to 279, depending on the number of waves invol ved. Results. Participants with scores of 4+ on the Cognitive Decline scale at W ave 3 showed substantial deterioration over the previous 7-8 years. Scores of 4+ at Wave 1 predicted mortality and further cognitive deterioration. Conclusions. The Cognitive Decline scale allows a valid retrospective asses sment of change and has predictive validity for subsequent cognitive deteri oration and increased mortality. Copyright (C) 2001 John Wiley & Sons, Ltd.