Assessment of post-stroke quality of life in cost-effectiveness studies: the usefulness of the Barthel Index and the EuroQoL-5D.

Stroke is a major cause of death and long-term disability in Western societies and constitutes a major claim on health care budgets. We address the problem of estimating quality adjusted life years (QALYs) for use in cost-effectiveness studies of stroke interventions. In the acute phase after stroke--at stroke onset and during rehabilitation--many patients are physically or mentally not able to (self-)report their quality of life. Missing values may obviously bias cost-effectiveness results. We have examined the direct relationship between a conventional clinical scale of functional status that is suited for proxy-assessment (Barthel Index (BI)) and a measure of health related quality of life (EuroQoL-5D). Based on data collected within the framework of an evaluation of three stroke-service experiments in The Netherlands (n = 598, 6 month follow-up), we established a plausible and significant relationship between the measures. Health related quality of life (HRQoL) is -0.25 for patients with a BI of 0, and with each additional point HRQoL increases with 0.05. Independent patients (BI 20) get a HRQoL is 0.75, which corresponds to the general population reference score for our sample. BI scores may be used as proxy for HRQoL in case of missing values on EuroQoL-5D.