Abstract
Background and Aim: The severe respiratory insufficiency (SRI) questionnaire is a validated, commonly used tool for measuring health related quality of life (HRQL) in patients with chronic hypercapnic respiratory failure (CHRF) but the minimal clinically important difference (MCID) has not been established. The aim of this study is to establish the MCID of the SRI-questionnaire in patients with severe chronic obstructive pulmonary disease (COPD) treated with noninvasive ventilation for 6 months.
Patients and Method: Data were analyzed from 108 severe but stable COPD patients with CHRF, initiated on chronic non-invasive ventilation (NIV). A combination of clinical and patient-reported anchors were used to define de MCID of the SRI domain and summary scores using lineair univariate regression analyses. Forced expiratory volume in one second (FEV1), six-minute walking distance (6MWD), the Hospital Anxiety and Depression Scale (HADS), daytime arterial pressure of carbon dioxide and bicarbonate were entered as anchors. In addition we used a global rating scale (GRS) of change in perceived health to estimate the MCID.
Results: The FEV1, 6MWD and HADS correlated to the change in the SRI and were suitable as anchors. The MCID of the SRI, estimated with these anchors and the GRS, was 5.3 points, and ranged from 0.2 to 10.0 points for the 7 SRI domains.
Conclusion: The MCID of the SRI summary score is 5.3 points, in patients with severe COPD and CHRF. This is the first estimated of the MCID of the SRI and would help to value the observed change in HRQL in clinical trials and enables the use of the SRI as a primary outcome in futere trials.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 3420.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020