Psychometric properties of the German version of the health-related quality of life in stroke patients (HRQOLISP) instrument

Abstract

Objective: There is lack of a German-language holistic stroke-specific health-related quality of life (HRQOL) measure with therapeutically-oriented domains. The objective of this study was to investigate the psychometric properties of the HRQOL in stroke patients (HRQOLISP) questionnaire in German stroke survivors.

Methods: Following standard procedure for cross-cultural validation, the HRQOLISP was translated into German. It was completed by 103 German stroke patients and 50 apparently healthy controls. Acceptance, ceiling and floor effects, reliability, as well as content, construct, factorial and known-group's validity were analysed. Stratification was according to modified Rankin, stroke levity and National Institute of Health stroke scales.

Results: The HRQOLISP was acceptable and holistic with neither ceiling nor floor effect. One-factor solution explained >40% of the variance for most domains. Two-factor solution explained 82% of the variance for the global HRQOL consistent with the conceptual framework distributing the therapeutically-oriented domains into two spheres. Cronbach's α ranged from 0.77 to 0.92 for the domains. The HRQOLISP, though lengthy, covered the entire spectrum of stroke-related HRQOL with no additional item suggested by the German stroke patients. The HRQOLISP demonstrated good convergent and discriminant validity as well as excellent 'known groups' validity across disability and stroke severity strata.

Conclusions: The German version of the HRQOLISP is the first holistic, stroke-specific HRQOLISP measures with therapeutically-oriented domains to be validated in Germany. It is acceptable, reliable and valid but needs to be validated in proxies to facilitate its utility among stroke patients with severe communication problems.

Keywords: HRQOL; HRQOLISP; Stroke rehabilitation; quality of life; reliability; validity.