Dutch translation and cultural adaptation of the LYMPH-Q, a new patient-reported outcome measure for breast cancer-related lymphedema

Background The LYMPH-Q Upper Extremity module is a new patient-reported outcome measure (PROM) developed to assess patient outcomes of breast cancer-related arm lymphedema (BCRL). Content for the LYMPH-Q Upper Extremity Module was developed from the extensive input of patients and experts in the field of breast surgery and breast cancer-related lymphedema. Rasch Measurement Theory analysis was used to assess psychometric properties. The aim of this study was to perform a Dutch translation and cultural adaptation of the LYMPH-Q Upper Extremity Module. Methods The translation process was performed in accordance with the guidelines of the International Society for Pharmacoeconomics and Outcomes Research (ISPOR).The process included two forward translations, two back translations, and cognitive debriefing interviews with patients with BCRL. Results Comparison of the two forward translations showed that the translations for most items (n= 60; 88.2%) were conceptually consistent between the two translators. Translations of the remaining items were reviewed and discussed until consensus was reached. Three items in the back translation had a different meaning when compared to the original English version and required re-translation. The resultant Dutch version of the LYMPH-Q was tested in a series of cognitive debriefing interviews with seven patients and showed good content validity. Conclusions The translation and cultural adaptation process resulted in a conceptually equivalent Dutch version of the LYMPH-Q Upper Extremity Module. This new PROM can now be used in clinical practice and research settings to evaluate outcomes in patients with BCRL.