Development of instruments to measure counselees' knowledge of Down syndrome

Since approximately 10% of counselees coming to genetics clinics are concerned with Down syndrome, the development of short measures of knowledge of Down syndrome for evaluation could have widespread application. The purpose of this study was to design efficient, self-administered questionnaires of simple vocabulary to measure knowledge and understanding of Down syndrome before and after genetic counseling. Twenty-six previously piloted questions were administered to nurses, graduate students in Medical Genetics, special education teachers, and parents of children with Down syndrome (n = 126). A coefficient alpha of 0.842 indicated strong reliability. The content of the questionnaire was distributed into three categories: genetic knowledge, recurrence risk, and prenatal diagnosis. From the items (1) which had less than 85% correct responses, and (2) which fell into just one of the three categories, 12 questions were selected as a post-test (coefficient alpha of 0.749). Eight additional questions were then extracted (coefficient alpha of 0.56) as a pretest. The pretest predicted 53.3% of the variance of the post-test. The use of these instruments before and after counseling can be an aid in evaluating counseling and in comparing various approaches for effectiveness.