Health related quality of life in patients with idiopathic pulmonary fibrosis in clinical practice: insights-IPF registry

Background: The INSIGHTS-IPF registry provides one of the largest data sets of clinical data and self-reported patient related outcomes including health related quality of life (QoL) on patients with idiopathic pulmonary fibrosis (IPF). We aimed to describe associations of various QoL instruments between each other and with patient characteristics at baseline. Methods: Six hundred twenty-three IPF patients with available QoL data (St George's Respiratory Questionnaire SGRQ, UCSD Shortness-of-Breath Questionnaire SoB, EuroQol visual analogue scale and index EQ-5D, Well-being Index WHO-5) were analysed. Mean age was 69.6 +/- 8.7 years, 77% were males, mean disease duration 2.0 +/- 3.3 years, FVC pred was 67.5 +/- 17.8%, DLCO pred 35.6 +/- 17%. Results: Mean points were SGRQ total 48.3, UCSD SoB 47.8, EQ-5D VAS 66.8, and WHO-5 13.9. These instruments had a high or very high correlation (exception WHO-5 to EQ-5D VAS with moderate correlation). On bivariate analysis, QoL by SGRQ total was statistically significantly associated with clinical symptoms (NYHA; p < 0.001), number of comorbidities (p < 0.05), hospitalisation rate (p < 0.01) and disease severity (as measured by GAP score, CPI, FVC and 6-min walk test; p < 0.05 each). Multivariate analyses showed a significant association between QoL (by SGRQ total) and IPF duration, FVC, age, NYHA class and indication for long-term oxygen treatment. Conclusions: Overall, IPF patients under real-life conditions have lower QoL compared to those in clinical studies. There is a meaningful relationship between QoL and various patient characteristics.