Table 4.

Adjusted Cox regression model

	HR	95% CI	P Value	AIC
Baseline periostin (SD units)	1.47	1.03–2.10	0.033	154.27
Age	1.00	0.95–1.05	0.876
Male	0.96	0.35–2.67	0.943
History of smoking*	2.32	0.52–10.29	0.268
Baseline FVC %predicted	1.01	0.98–1.04	0.546
Baseline DLCO %predicted	0.99	0.95–1.03	0.673

SD, SD (of baseline periostin). HR can be interpreted as risk of progression increasing 1.5-fold for an increase of 1 SD in baseline periostin levels, when age, sex, history of smoking, and baseline pulmonary physiology tests were held constant. n = 50 [54–50 = 4 patients had missing values for predictors in multivariate model and were removed (3 removed from model because of missing Dl_CO and 1 removed because of missing FVC, FEV₁, and Dl_CO)], 20 events.

^*Patient was a past or current smoker vs. never smoker.