Estimating premorbid WAIS-R intelligence in the elderly: An extension and cross validation of new regression equations

Recently developed equations that combine WAIS-R subtests and demographic information to estimate premorbid intelligence were evaluated in persons 75 years and older. The equations underestimated the obtained IQs of elderly persons. Therefore, new equations were developed using the old age WAIS-R standardization sample. The new equations cross-validated well and demonstrated adequate abitity to detect possible intellectual deterioration in a brain damaged sample. The demographic formulas of Barona, Reynolds, and Chastain worked as well as the new equations in suggesting possible deterioration in a sample of elderly persons with chronic and diffuse cognitive impairment