Validity of the SS-QOL in Germany and in Survivors of Hemorrhagic or Ischemic Stroke

Abstract

Objective. The Stroke-Specific Quality of Life Scale (SS-QOL) is a recently developed measure to assess health-related quality of life in stroke patients. The objective of this study was to translate the American version of the SS-QOL and examine the validity of the German proxy version, in both ischemic and hemorrhagic stroke survivors. Methods. The translation was conducted according to published guidelines. The validation was performed in consecutive adult stroke survivors. Data were obtained 1 year after discharge. To examine the dimensionality of the SS-QOL, factor analyses were conducted. The validity was examined by the associations of the subscales with the Functional Independence Measure and Short Form 36. Results. The literal translation revealed no major changes between the American and the German versions of the SS-QOL. Three hundred seven stroke survivors were included in the study. Unlike the 1st validation study, most of the variance could be explained by 8 instead of 12 factors; therefore, the 8-factor solution was further examined. The validity of the SS-QOL total score and “observable” scales such as “activities” was shown. Conclusions. For the German proxy version of the SS-QOL, an 8-factor solution was found to be the most appropriate. The psychometric properties of these 8 subscales were good or excellent with respect to internal consistency. The validity of the total score was shown, but some subscales (energy, mood, and thinking) failed the hypothesized associations. Therefore, the SS-QOL needs to be further explored in other settings and populations.