PURPOSE:To professionally translate and validate an easy-to-use tool for assessing respiratory symptoms, sleep quality and side effects of the ventilator in patients undergoing long-term non-invasive ventilation (NIV) from the original French into German in order to broaden the area of operation for the S3-non-invasive ventilation (S3-NIV) questionnaire.

METHODS:In a prospective trial patients on long-term NIV were recruited. Professional translation and cultural adaptation was obtained via translation-back-translation using the ABC-Scheme, that compared each individual question and its language neutrality. Afterwards patients in a stable clinical state filled out the German S3-NIV questionnaire alongside the German St. Georges Respiratory Questionnaire to proof convergent validity via Spearman correlation. Internal Consistency was established using CronbachŽs ?.

RESULTS:Sixty patients (female 56.6%) with long-term NIV for different underlying diseases were  enrolled (COPD: n = 58, 96.6%; OHS: n = 2, 3.3%). Mean age was 65.3 years (SD: 8.5), mean body mass index (BMI) 29.4 kg/m2. Internal consistency was good (CronbachŽs ?: summary score = 0.74; ?respiratory symptoms? = 0.66; ?sleep and side effects? = 0.69). Convergent validity in relation to the SGRQ was high (summary score: rho = ?.61, p <0.001; ?respiratory symptoms? rho = ?.64, p <0.001). Exploratory factor analysis led to a variance of 39.51% and unveiled two components.

CONCLUSION:The German version of the S3-NIV questionnaire is a valid, simple tool for assessing patient-centered outcomes in routine clinical care of patients undergoing long-term NIV.