The relationship between descriptive and valuational quality-of-life measures in patients with intermittent claudication

The study objective was to assess the relationship between descriptive and valuational quality-of-life measures in patients with intermittent claudication. In telephone interviews, 68 patients completed a questionnaire consisting of a descriptive health status measure (RAND 36-item Health Survey 1.0), and several valuational measures (standard gamble, time tradeoff, rating scale, and McMaster health utility index). All measures demonstrated reduced quality of life in the patients. Scores on the RAND-36 dimensions correlated moderately well with the rating scale and McMaster health utility index (R = 0.37-0.67) but less well with the standard gamble and the time tradeoff (R = 0.10-0.46). Multiple regression analysis demonstrated that 28% of the variance in the time-tradeoff values and 14% of the variance of the standard-gamble utilities could be explained by the best combination of RAND dimensions. These results suggest that answers to descriptive health-status questions cannot reliably predict standard-gamble utilities or time-tradeoff values.