Reliability and validity of utility approach to measuring health related quality of life: An example of patients on hemodialysis

The measure of health-related quality of life has been used progressively in clinical decision making, public health priority setting, assessing the effectiveness of health programs and economic cost-utility analysis. The purpose of this study is to evaluate the reliability and validity of two utility measurement techniques including time tradeoff and rating scale in the measure of health-related quality of life in order that we could develop an indicator for health policy decision and program evaluation based on Chinese cultural background. Subjects of this cross- sectional study consisted of all the patients of end-stage renal disease receiving maintenance hemodialysis at the hemodialysis room of three teaching hospitals in the Taipei between August 1993 and November 1993. Interviews were undertaken by standardized interviewers with a structured questionnaire. 125 subjects completed the interview. The response rate was about 90%. The results showed that both time tradeoff and rating scale measurement techniques got consistent results by different interviewers and method and at different interviewing time and situations. These two measurement techniques had good performance in the assessment of validity including construct validity and criterion-related validity. The utility values measured by standard gamble, time tradeoff, and rating scale were 0.75, 0.61, and 0.57 respectively. Standard gamble, time tradeoff and rating scale are all reliable and valid techniques in the measure of health-related quality of life. Based on feasibility, the time tradeoff and rating scale methods are more popular with most investigators. The rating scale method is easiest to administer and appears to yield results that are as valid as any other method. Thus, this would seem to be the method of choice in large-sample studies.