Responsiveness of the Lymphedema Functioning, Disability, and Health Questionnaire for Upper Limb Lymphedema in Patients with Breast Cancer-Related Lymphedema.

Background: The Lymphedema Functioning, Disability, and Health questionnaire for Upper Limb Lymphedema (Lymph-ICF-UL) is a health-related quality-of-life questionnaire for patients with breast cancer-related lymphedema. Previous testing of this questionnaire showed very good psychometric properties; however, responsiveness has not yet been established. The aim of this study was to determine its internal and external responsiveness. Methods and Results: Ninety-five patients treated with decongestive lymphatic therapy in a longitudinal trial were recruited. Patients completed the Lymph-ICF-UL twice within a time interval of 7 weeks ("intensive group" receiving intensive treatment; n = 73) or 3 months ("stable group" receiving maintenance treatment; n = 22), and once the Global Perceived Effect (GPE) questionnaire at the second time point. The significance of change in scores and standardized response mean (SRM) were determined for the total and domain scores. Correlations between Lymph-ICF-UL and GPE were ascertained. In addition, the minimal clinical important difference (MCID) was determined. The Lymph-ICF-UL total score changed significantly in the intensive group (p < 0.001) and nonsignificantly for those in the stable group (p = 0.25). The SRM represented moderate responsiveness (0.65). Patients who reported a clinical improvement ( = responders) after intensive treatment showed a significant decrease in total score (p < 0.001), this was also the case for nonresponders (p < 0.001). Lymph-ICF-UL total and domain scores showed nonsignificant weak correlations with the GPE (p > 0.05). There was a significant difference in mean total score changes between responders and nonresponders (p < 0.001). MCID for the total score was 9%. Conclusion: The Lymph-ICF-UL is responsive to change after decongestive lymphatic therapy. No correlations were found between Lymph-ICF-UL change scores and GPE. Future studies should be conducted in a clinical setting, with more variability between participants and their treatment responses.