Qualitative Comparison of the Reliability of Health Status Assessments With the EuroQol and SF-36 Questionnaires After Stroke

Abstract

Background and Purpose—The reliability of the EuroQol and SF-36 questionnaires after stroke is not known. We therefore aimed to assess and compare the test-retest reliability of both instruments in a group of stroke patients. Methods—A total of 2253 patients with stroke entered by United Kingdom hospitals in the International Stroke Trial were randomized to follow up with either the EuroQol or the SF-36 instruments. For both instruments, we randomly selected one third of respondents and asked them to complete another, identical questionnaire. We assessed test-retest reliability using agreement statistics: unweighted κ statistics for the categorical domains of the EuroQol and intraclass correlation coefficients for the EuroQol visual analog scale, utility scores, and SF-36. Results—For the five categorical domains of the EuroQol, reproducibility was generally good (κ ranged from 0.63 to 0.80). The reproducibility of the domains of the SF-36 was qualitatively similar for all the domains except mental health...