Translation, Cross-Cultural Adaptation and Validation of the Lymphedema Quality of Life Questionnaire (LYMQOL) in German-Speaking Patients with Upper Limb Lymphedema.

The LYMQOL is the most frequently translated, validated, objective tool for assessing Health-Related Quality of Life (HRQoL) in individuals with upper limb lymphedema (ULL). There have been adaptations and validations in a number of different countries. While a German version of LYMQOL Leg for lower limb lymphedema is available, a validated translation of LYMQOL Arm to German is lacking. We aimed to perform a cross-cultural adaption and translation according to ISPOR principles. Patients suffering from ULL from Germany, Austria, and Switzerland (n = 52) were questioned twice using the translated LYMQOL Arm, SF-36, and an evaluation questionnaire. The assessment of the content validity and face validity proved this version of LYMQOL Arm to be acceptable for interviewing German-speaking patients with ULL in Germany. Comparison of LYMQOL Arm and SF-36 demonstrated good construct validity. Test-retest reliability was moderate to good (intraclass correlation coefficients 0.66-0.73). Cronbach's alpha values varied between 0.79 and 0.89 in both interviews, indicating good internal consistency. Factor analysis revealed a cumulative variance of 59.5% for the four domains of the questionnaire. There was no significant association between lymphedema stage and LYMQOL Arm score. This trial tested the appropriateness of the German version of the LYMQOL Arm for measuring HRQoL in German-speaking individuals with ULL.