Quality of life among Swedish patients after stroke: psychometric evaluation of SF-36.

Abstract

Few studies have evaluated the scale assumptions of the Medical Outcomes Study 36-item Short-Form (SF-36) with stroke survivors. The aims of this study were to evaluate the scale assumptions of SF-36 using Swedish patients after stroke and to compare patients' quality of life with that of a healthy population. Cross-sectional study. SF-36 was tested in 188 patients (mean age 74 years) with acute stroke consecutively enrolled from a stroke unit in southern Sweden during 2003-05. Data were collected by interview during a home visit 2-3 weeks after discharge. Psychometric analyses were conducted, and stroke survivors' quality of life was compared with a Swedish normal population. The internal consistency reliability was >0.70 for all scales. There were notable floor and/or ceiling effects for 3 scales. For 7 scales, there was the expected association with the 2 summary scales. Compared with a normal Swedish population, stroke has a negative effect on health-related quality of life, especially for patients aged 45-54 years. SF-36 functions well as a measure of health-related quality of life in Swedish patients after stroke, but the 2 summary scales have shortcomings. Our findings support good divergent validity of SF-36 for discriminating health-related quality of life of stroke groups and normal populations.