RELIABILITY OF THE HEALTH UTILITIES INDEX - MARK-III USED IN THE 1991CYCLE-6 CANADIAN GENERAL SOCIAL SURVEY HEALTH QUESTIONNAIRE

This study presents information on the test-retest reliability of the Health Utility Index-Mark III (HUI) system used in cycle 6 of the Cana dian General Social Survey (GSS). The HUI system used in this reliabil ity study consists of an eight-attribute health status classification system (HSCS) and a function for generating a summary score of health- related quality of life. To estimate test-retest reliability, a strati fied random sample of individuals (n = 506) completing GSS telephone i nterviews during August and September, 1991 were interviewed again 1 m onth later. Weighting adjustments based on the probability of selectio n were invoked during the analyses to provide unbiased estimates of te st-retest reliability for all GSS respondents in the August-September period. The results indicate that the individual questions, attributes and provisional index scores generally provided reliable information on health status in the GSS. The exceptions to this were limitations i n speech and dexterity which were reported very infrequently. Kappa es timates of test-retest reliability for individual questions varied fro m 0.184 to 0.766. For the eight attributes, kappa estimates varied fro m 0.137 to 0.728. Using the provisional index scores to quantify healt h overall, a test-retest reliability of 0.767 was obtained (intra-clas s correlation coefficient).