ABSTRACT
BACKGROUND: Respiratory insufficiency in COPD may present as hypoxic and/or hypercapnic respiratory failure treated with long-term oxygen therapy (LTOT) and/or noninvasive ventilation (NIV) with LTOT. The Severe Respiratory Insufficiency Questionnaire (SRI) is a tool for the assessment of health-related quality of life (HRQOL) in subjects receiving NIV. However, it remains unclear whether the SRI is also capable of assessing and discriminating HRQOL in subjects receiving LTOT. METHODS: Stable subjects with COPD receiving LTOT or NIV + LTOT (NIV) were prospectively recruited and completed the SRI, lung function tests, and blood gases. Confirmatory factor analysis for construct validity and internal consistency reliability were calculated. RESULTS: One hundred fifty-five subjects were included (113 LTOT, 42 NIV). The Cronbach α coefficient of the 7 subscales ranged between 0.69 and 0.89 (LTOT) and between 0.79 and 0.93 (NIV), respectively. In both groups, confirmatory factor analysis revealed a one-factor model for the SRI summary scale; in 5 subscales, one- or 2-factor models could be established. Group differences in the SRI subsets were all P <.05 (except for physical functioning) with higher scores in subjects receiving NIV. CONCLUSIONS: The SRI showed high reliability and validity in subjects with COPD receiving LTOT. Subjects receiving LTOT had lower SRI scores, indicating a poorer HRQOL compared with subjects with established NIV and LTOT.