Abstract
Earlier papers have detailed the conceptualization, development, and testing of the New castle Independence Assessment Form (NIAF-R), an alternative global outcome mea sure. This article establishes the predictive validity of the measure. Predictive validity was examined by applying two different prediction models, using functional status and return to work (RTW) as the two outcome variables. Multiple linear and logistic re gression analyses indicated that the NIAF-R, when incorporated in equations with age and injury severity, the latter determined by length of coma, was consistently predict ing functional status from as early as 8 weeks and return to work from as early as 12 weeks post-injury. Prediction of functional status was especially significant, with the NIAF-R accounting for up to 90 percent of the variance. Prediction of return to work, although consistent, was less powerful. Implications for the validity of the NIAF-R, with partic ular reference to prognosis and rehabilitation planning, are presented. Key Words: New castle Independence Assessment Form-Research (NIAF-R)—Neurologic rehabilita tion—Functional assessment—Outcome measurement—Predictive validity.