The validation of a diabetes patient knowledge test.

Diabetes knowledge tests, used in conjunction with measures of patient attitudes and behaviors, can provide a useful basis for assessing educational needs and designing appropriate instructional experiences. Accurate decisions require instruments that measure patient knowledge of diabetes and its management with high reliability and validity. Data obtained from more than 950 administrations of two parallel forms of a Diabetes Patient Knowledge Test have provided documentation of patient knowledge levels, insight into the effectiveness of educational programs, and support for ongoing program revisions. These data have also allowed study of the psychometric properties of the test instruments, including factor structure, reliability, and validity. Each test form has an overall reliability of 0.89 and the forms are of equal difficulty. Five subcomponents (factors) labeled "Carbohydrates," "Blood Sugar," "Basics," "Food Exchanges," and "Insulin Administration" are measured in the tests. Evidence of content, construct, concurrent, and discriminant validity has been demonstrated.