Reliability and validity of Turkish version of lymphedema life impact scale

Abstract

Objectives: In this study, we aimed to investigate the validity and reliability of the Turkish adaptation of the Lymphedema Life Impact Scale (LLIS). Patients and methods: A total of 106 patients (103 females, 3 males; mean age 53.6±11.8 years; range, 28 to 83 years) with lymphedema who were admitted to the lymphedema outpatient clinics of our hospital between May 2016 and November 2016 were included. Reliability of the scale was assessed by internal consistency (Cronbach’s alpha coefficient) and test-retest method. Validity of the scale was examined using the factor analysis and correlating the 12-Item Short-Form Health Survey (SF-12), European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30), Disabilities of Arm Shoulder and Hand (DASH), and the Lower Extremity Functional Scale (LEFS). Results: For internal consistency, Cronbach’s alpha coefficients of all subscales ranged between 0.771 and 0.865 and calculated as 0.916 as the total score. In test-retest reliability, the correlation coefficient ranged between 0.963 and 0.985 for each subscale and calculated as 0.991 for the total score. In the validity analysis, factor analysis demonstrated a probable structure of three factors which together explained 58.9% of total variance and the Turkish adaptation of the LLIS correlated with other comparison measures used in this study. Conclusion: This study shows that the Turkish version of the LLIS is a valid and reliable scale to evaluate the quality of life in the Turkish population with lymphedema.