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

<b>Objectives:</b> 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. <b>Methods:</b> 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. <b>Results:</b> 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. <b>Conclusion:</b> 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.