The utility of health states after stroke: a systematic review of the literature.

BACKGROUND: To perform decision analyses that include stroke as one of the possible health states, the utilities of stroke states must be determined. We reviewed the literature to obtain estimates of the utility of stroke and explored the impact of the study population and the elicitation method. SUMMARY OF REVIEW: We searched various databases for articles reporting empirical assessment of utilities. Mean utilities of major stroke (Rankin Scale 4 to 5) and minor stroke (Rankin Scale 2 to 3) were calculated, stratified by study population and elicitation method. Additionally, the modified Rankin Scale was mapped onto the EuroQol classification system. Utilities were obtained from 23 articles. Patients at risk for stroke assigned utilities of 0.26 and 0.55 to major and minor stroke, respectively. Stroke survivors assigned higher utilities to both major (0.41) and minor stroke (0.72). The EuroQol completed by stroke survivors revealed a utility of 0.32 and 0.71 for major and minor stroke, respectively. Utilities elicited by the Standard Gamble were generally higher, while those obtained by the Visual Analogue Scale were lower than the Time Trade Off values. Remaining variation between utilities may be caused by differences in definitions of the health states. The mapped EuroQol indicated a utility of 0.64 for minor stroke and a value just below zero for major stroke.
CONCLUSIONS: For minor stroke, a utility between 0.50 and 0.70 seems to be reasonable for both decision analyses and cost-effectiveness studies. The utility of major stroke may range between 0 and 0.30 and may possibly be negative.