The translation and validation of Bahasa Malaysia version of the lymphedema functioning, disability and health questionnaire for upper limb lymphedema

Abstract

Breast cancer-related upper limb lymphedema (BCRL) is the most prevalent morbidity of post-breast cancer treatment that could negatively affect quality of life (QoL). Exploring QoL using a valid and reliable questionnaire is an essential part of BCRL treatment. So far, there is no BCRL QoL related questionnaire is available in Bahasa Malaysia (BM) and no reports on the QoL among patients with BCRL in local setting. Hence, the general aim of this study is to determine the validity and reliability of the newly translated Lymph-ICF-UL BM. This study was conducted in two phases. Phase one was a systematic review assessing psychometric properties of available questionnaires measuring QoL in BCRL population, that conducted using COSMIN guidelines and checklist. Phase 2 was a cross-sectional study that consisted of: 1) translation process of the questionnaire obtained from phase 1 using Sousa’s guideline; 2) face validity in five patients; 3) content validity in six experts and analyzed using CVI and modified Kappa statistics; 4) construct validity that analyzed using CFA and internal consistency that analyzed using Cronbach’s α in 107 patients; 5) test-retest reliability which analyzed using ICC, SEM, and LOA in 21 patients; and 6) QoL assessment in 107 patients to compare the QoL scores between marital status, working status, ethnicity, BMI groups, and BCRL stages that analyzed using Mann-Whitney U test and Kruskal-Wallis test. The Lymph-ICF-UL was the most suitable questionnaire according to the systematic review. Translations process showed no major loss in general meaning of the sentences. Two items were eliminated following the patients’ and experts’ suggestion. All patients found the scoring system and 27 items in the Lymph-ICF-UL BM clear and relevant, suggesting good face validity. Sufficient CVI and modified kappa values were found, indicating good content validity. CFA showed acceptable fit indices which suggested a good construct validity. Cronbach’s α values ranged from 0.67 to 0.95, indicating good internal consistency. ICC ranged from 0.88 to 0.99, SEM was 2.29 – 6.15, and Bland-Altman plot showed an agreement between two test occasions, demonstrating a good test-retest reliability. In conclusion, the Lymph-ICF-UL BM has good validity and reliability. Moreover, there was a significant mobility activities scores differences between the BCRL stages, especially between stage 0 BCRL and stage 2 BCRL. This finding suggested that BCRL stages did affect the QoL of patients