Supplementary Material for: Sex differences in IPF: data from the German INSIGHTS-registry

Background: Idiopathic pulmonary fibrosis (IPF) preferentially occurs in male patients and controversial results in gender-specific differences including overall mortality have been reported. Methods: The INSIGHTS IPF registry was a non-interventional, prospective cohort study including IPF patients from 20 interstitial lung disease expert centres in Germany. Sex-related disparities were analyzed regarding comorbidities, clinical course and survival. Results: Of the 1043 IPF patients included, 842 (80.7%) were male and 201 (19.3%) were female. Male patients were more likely to have a history of smoking (p<0.001) and environmental exposure, especially metal dust, wood dust and solvents (p=0.032). While males at baseline had a higher prevalence of coronary artery disease, atrial fibrillation, emphysema and obstructive sleep apnoea syndrome, in females, gastro-oesophageal reflux disease and depression or depressive disorders were more frequent. Female IPF patients had more frequently a history of immunosuppressive therapy (p=0.003). Regardless of gender, the INSIGHTS IPF cohort as a whole showed a progressive worsening of lung function parameters over time. All-cause mortality did not differ between females and males (HR: 0.81; 95%-CI: 0.63; 1.04; p=0.093) and female gender was not a significant predictor for mortality in IPF (HR 0.74; 95%-CI: 0.54–1.03; p=0.071). Interestingly, the GAP score underestimated the observed 2-years and 3-years mortality in females in GAP Stage II. Conclusion: In conclusion, in the German INSIGHTS IPF registry no differences in lung function decline and survival could be observed between female and male patients with IPF, indicating differences between IPF cohorts from the USA and Europe.