Validity and reliability of the Dutch version of the S3-NIV questionnaire to evaluate long-term noninvasive ventilation

ObjectivesNoninvasive ventilation (NIV) is an effective treatment for chronic respiratory failure (CRF). Patient-centered outcomes need to be evaluated regularly and the S3-NIV questionnaire seems an applicable tool. We translated this short, self-administered questionnaire into a Dutch version and tested its construct validity and reliability.MethodsAn observational study was conducted, including 127 stable long-term NIV users with CRF or complex sleep related breathing disorders due to different underlying diseases: chronic obstructive pulmonary disease (25%), slowly progressive neuromuscular disorders (35%), rapidly progressive neuromuscular disorders (12%) and 'other disorders' (28%) including complex sleep apnea and obesity hypoventilation syndrome. Construct validity and reliability were tested.ResultsThe Dutch version of the questionnaire was obtained after a translation and back-translation process. Internal consistency of the total score was good (Cronbach's alpha coefficient of 0.78) as well as for the 'respiratory symptoms' subdomain and the 'sleep and side effects' subdomain (Cronbach's alpha coefficient of 0.78 and 0.69, respectively). The reproducibility was excellent with an intraclass correlation of 0.89 (95% CI 0.87-0.93). Construct validity was good for the 'respiratory symptoms' subdomain.ConclusionThe Dutch S3-NIV questionnaire is a reliable and valid tool to evaluate symptoms, sleep, and NIV related side effects in long-term NIV users.