Intermittent claudication: symptom severity versus health values

Abstract

Objective: The objective of this study was to obtain health values from patients with intermittent claudication with five different instruments and to study the construct validity of these measures of health-related quality of life by examining their relation with symptom severity.

Methods: We included all patients with intermittent claudication who participated in an exercise program of the Department of Internal Medicine at our university hospital (n = 92). Health value instruments included the verbal rating scale, time trade-off, standard gamble, EuroQol, and the Health Utilities Index (Mark III). Symptom-free walking distance was used as a measure of symptom severity.

Results: For all instruments the average health values in groups of patients with a symptom-free walking distance < or = 150 m were lower than the average values in patients with a greater walk distance, but the differences for the time trade-off and the standard gamble were small, and only the differences for the verbal rating scale and the EuroQol were statistically significant. At the individual patient level considerable heterogeneity was seen, and the statistical association of the symptom-free walking distance with health values varied from poor to moderate (Spearman rank correlations, 0.03 to 0.48; p values, 0.003 to 0.78).

Conclusion: At least for the verbal rating scale and the EuroQol, the results of our study provide evidence of the validity of the various health value instruments in a population of patients with peripheral arterial occlusive disease.