TABLE 2

Risk prediction models for investigator-reported and adjudicated confirmed or suspected acute exacerbations

Step	Risk factor analysis			Final model
	Model variable^#	p-value^¶	AIC⁺	HR (95% CI)^§

Investigator-reported acute exacerbations	FVC % predicted at baseline^ƒ	<0.0001	830.217	0.67 (0.55–0.80)
	Supplemental oxygen use at baseline	0.0018	824.565	2.47 (1.37–4.47)
	Antacid medication use at baseline	0.0873	823.706	1.50 (0.91–2.47)
	Randomisation to nintedanib	0.1150	823.271	0.66 (0.40–1.08)

Adjudicated confirmed or suspected acute exacerbations	FVC % predicted at baseline	0.0006	483.723	0.67 (0.53–0.86)
	Randomisation to nintedanib	0.0010	475.169	0.33 (0.16–0.66)
	Antacid medication use at baseline	0.0676	473.938	1.78 (0.92–3.43)
	Former or current smoker	0.0938	472.805	2.13 (0.89–5.13)
	Supplemental oxygen use at baseline	0.1322	472.870	1.85 (0.80–4.29)

FVC: forced vital capacity. ^#: covariates that achieved p<0.2 in the stepwise selection procedure are shown. The variables are shown in the order that they were selected into the model. ^¶: p-value of the likelihood chi-squared test used in the decision to add the variable to the model. ⁺: Akaike information criterion (AIC) was calculated for the model at the end of each selection step. Lower AIC values indicate better performance of the model. ^§: based on the final model, i.e. including all the variables that were selected during the stepwise selection procedure. ^ƒ: hazard ratio (95% CI) is calculated for FVC % predicted 10% higher at baseline.