DEVELOPMENT OF THE CAMBRIDGE CONTEXTUAL READING TEST FOR IMPROVING THE ESTIMATION OF PREMORBID VERBAL INTELLIGENCE IN OLDER PERSONS WITH DEMENTIA

Objectives. The Cambridge Contextual Reading Test (CCRT), which sets t he NART words within semantic and syntactic context, has been shown to yield a higher prediction of premorbid intelligence than the National Adult Reading Test (NART) for patients with mild/moderate dementia (B eardsall & Huppert, 1994). This study validates and standardizes the C CRT in a sample of healthy older persons. Design. The CCRT was validat ed against WAIS-R verbal IQ (VIQ) and the Mill Hill Vocabulary Test (M HVT). Regression equations were used to compare predictions of WAIS-R VIQ from CCRT and demographic variables. A conversion table was constr ucted for predicted VIQ from the equation derived from CCRT scores. Me thods. Seventy-three healthy British older persons aged over 70 years completed the CCRT, NART, WAIS-R verbal subtests and MHVT. Results. Th e benefit of context was greatest for those with lowest word reading a bility. The CCRT was satisfactorily correlated with VIQ and the MHVT. Whereas the regression equation predicting VIQ using CCRT alone accoun ted for 61 per cent of the variance, 68 per cent was accounted for whe n demographic variables were included. Conclusions. The CCRT is a vali d measure of verbal ability for older persons. When accurate informati on about years of full-time education is available, prediction of verb al intelligence should be made combining CCRT with demographic variabl es. Otherwise, prediction should be made using CCRT alone. The CCRT ma y be used in preference to NART in neuropsychological batteries with o lder persons provided caution is exercised when language difficulties are indicated.