Assessment of disease impact in patients with intermittent claudication: discrepancy between health status and quality of life

Abstract

Objective: To describe similarities and differences between health status and quality of life in patients with intermittent claudication.

Methods: This was an observational study in the vascular outpatient department of a teaching hospital; it concerned 200 consecutive patients with intermittent claudication. Health status was assessed with the RAND-36, and quality of life was assessed with a reduced version of the World Health Organization Quality of Life assessment instrument-100. Scores were compared with those of sex- and age-matched healthy controls. Mann-Whitney U tests were used to detect statistically significant differences ( P < .01) between patients and healthy controls. Pearson correlations were calculated between health status and quality-of-life scores. Differences between correlations were examined by using Fisher z statistics. The upper and lower 10% of quality-of-life scores were compared with the response quartiles of the health status scores.

Results: Health status was significantly impaired in all domains. Quality of life was significantly worse with respect to aspects of physical health and level of independence and one global evaluative facets overall quality of life and general health. Quality-of-life assessment with the World Health Organization Quality of Life instrument disclosed patient-reported problems that had not been identified in health status. Conversely, patients did not regard all objective functional impairments as a problem. Pearson correlations ranged from 0.20 to 0.74. There were patients with excellent and very poor quality-of-life scores in nearly all the quartiles of the corresponding health status domains.

Conclusions: Health status and quality of life represent different outcomes in patients with intermittent claudication. In addition to functional restrictions as measured in health status, quality of life also permits a personal evaluation of these restrictions. Objective functioning and subjective appraisal of functioning are complementary and not identical. Combining these measures should direct treatment in a way that meets patients' needs.