Background: Quality of life (QOL) measures give patients the possibility to express subjective changes in wellbeing. We aimed to translate the radiation specific quality of life questionnaire (QOL-RTI) and the companion head and neck module (H&N) questionnaire into German and to test its reliability, validity and sensitivity.
Patients and methods: After translation and final revisions based on qualitative interviews with ten patients, 97 head and neck cancer patients were screened for eligibility. Patients answered the 38 items questionnaire at baseline and twice in week 4 of radiotherapy for test-retest reliability. Internal consistency was calculated using Chronbach's alpha. Patients also completed the functional assessment of cancer tool plus head and neck (FACT-G plus H&N) for concurrent validity. Item analyses were performed to test the sensitivity.
Results: Chronbach's alpha yielded alpha = 0.85 for the QOL-RTI and alpha = 0.80 for the H&N module, test-retest reliability scores were r = 0.87 and r = 0.83, respectively. The correlation of the QOL-RTI plus H&N and the FACT plus H&N was r = 0.79. Questionnaire sensitivity was supported by significant changes in the mean score of 45.8% of the QOL-RTI items and 78.6% of the H&N items between baseline and week 4 of radiotherapy.
Conclusions: The German version of the QOL-RTI was shown to be a reliable, valid and sensitive tool to assess the quality of life of patients undergoing radiotherapy. The H&N module is useful for patients undergoing treatment for head and neck cancer.