PSYCHOMETRIC DEVELOPMENT OF AN INSTRUMENT TO MEASURE ACQUISITION OF DIABETES KNOWLEDGE

Methods are described for validating a knowledge test for evaluating the information provided by ''About Your Diabetes,'' an interactive video program for educating patients with diabetes. The psychometric analysis included the estimation of: (i) content validity by a panel of judges; (ii) readability levels using three readability formulae; (iii) internal consistency using the Kuder-Richardson 20 formula; and (iv) item statistics, including the point-biserial correlation coefficient, difficulty index, and the ability of items to discriminate between control and experimental groups. The instrument was tested using a posttest-only control group design and was found to be sensitive to information acquisition resulting from exposure to the educational program. The final test instrument consisted of 33 questions, each exhibiting desirable psychometric properties. This project represents the first of a series of steps in the comprehensive evaluation of an innovative method for educating patients with diabetes.