Validation of the Polish version of Severe Respiratory Insufficiency Questionnaire.

Introduction: Improvement in the quality of life (QoL) is an essential outcome in patients with chronic respiratory failure (CRF). However, its reliable and comparative assessment is difficult in this highly heterogeneous group of patients. Severe Respiratory Insufficiency Questionnaire (SRI) has shown to have high psychometric properties to measure specific health-related QoL in patients with CRF due to different pathologies.

Objectives: The aim of this study was to validate the Polish version of the SRI.

Patients And Methods: The Polish version of the SRI was created according to the procedure of translation and back‑ translation of the original version. Patients with CRF treated with long‑term oxygen therapy (LTOT) or home mechanical ventilation (HMV) were invited to the study. Polish SRI and 36‑ Item Short Form Health Survey (SF‑36) questionnaires were completed during 2 consecutive visits scheduled at a 2-4 week interval. The results were statistically tested for validity, viability, and reliability. The time and ability of completing, sociodemographic and clinical data were recorded.

Results: A total of 113 patients were enrolled. Seventy‑ five participants (66%) completed the questionnaires without any assistance. A significant concurrent validity was confirmed by a correlation analysis between the SRI and the SF‑36 scales. An exploratory factor analysis explained 69% of the variance of the questionnaire. High internal consistency was proved by the Cronbach α coefficient 0.951 for the Summary Scale. Repeatability was very high for all subscales (intraclass correlation coefficient, 0.871-0.915) and for the summary score (0.923, P <0.001).

Conclusions: Our study demonstrated that the Polish version of the SRI is valid, reliable, and reproducible and may be used in research involving CRF.