Validation of the Lymphoedema Quality of Life Questionnaire (LYMQOL) in Swedish cancer patients.

Background: The aim of this study was to validate a translated Swedish version of the lymphoedema-specific quality of life questionnaire (LYMQOL) in a cohort of Swedish cancer patients with secondary lymphoedema of the limbs after cancer treatment.Material and methods: We recruited 102 patients with lymphoedema of the arms or legs after cancer treatment who were visiting lymphoedema therapists at the departments of oncology at the university hospitals in Linköping and Umeå. The LYMQOL questionnaires were translated forward and backward from English to Swedish. Content and face validity were evaluated. The construct validity was assessed by comparing the LYMQOL with the Short Form Health Survey (SF-36) and the perceived degree of lymphoedema of the limbs, respectively. Reliability was determined through test-retest. The internal consistency was assessed by determining Cronbach's alpha and by factor analysis.Results: The content and face validity assessments showed that LYMQOL was an easy, clear and not too long questionnaire to use for patients with lymphoedema. Construct validity was high in both versions when compared with the SF-36. The association between the degrees of perceived lymphoedema and the LYMQOL was only significant in the domains Function and Body Image in the arm version, whereas all domains in the leg version were significant. The reliability was good for the arm version (intra-class-correlation coefficients 0.53-0.87) and very good for the leg version (intra-class-correlation coefficients 0.78-0.90). The internal consistency was acceptable to excellent, with Cronbach's alpha values between 0.79-0.93 (arm-version) and 0.87-0.94 (leg-version). The factor analysis confirmed the usefulness of the four domains in the LYMQOL versions.Conclusions: This study confirmed the validity of the Swedish version of LYMQOL and demonstrated that LYMQOL may be a simple and useful tool for use in clinical practice and scientific contexts for evaluating QoL in patients with lymphoedema of the limbs.