PSYCHOMETRIC DEVELOPMENT OF AN INSTRUMENT TO MEASURE ACQUISITION OF DIABETES KNOWLEDGE

Methods are described for validating a knowledge test for evaluating t he information provided by ''About Your Diabetes,'' an interactive vid eo program for educating patients with diabetes. The psychometric anal ysis included the estimation of: (i) content validity by a panel of ju dges; (ii) readability levels using three readability formulae; (iii) internal consistency using the Kuder-Richardson 20 formula; and (iv) i tem statistics, including the point-biserial correlation coefficient, difficulty index, and the ability of items to discriminate between con trol and experimental groups. The instrument was tested using a postte st-only control group design and was found to be sensitive to informat ion acquisition resulting from exposure to the educational program. Th e final test instrument consisted of 33 questions, each exhibiting des irable psychometric properties. This project represents the first of a series of steps in the comprehensive evaluation of an innovative meth od for educating patients with diabetes.