Table 5.

Univariate analysis to identify factors associated with hospitalisation of patients with IPF during 3 months

Predictor parameter	Modality	Current-interval analysis		Previous-interval analysisa
		OR (95% CI)	p value	OR (95% CI)	p value
FVC%Pred at beginning of interval	For 10-unit decrement	1.08 (0.97, 1.21)	0.169	1.06 (0.95, 1.20)	0.305
Change in FVC%Pred over interval	For 10-unit decrement	1.28 (0.96, 1.70)	0.087	1.46 (1.10, 1.93)	0.008
Any drop in FVC%Pred during interval	Yes (vs no)	1.08 (0.80, 1.47)	0.611	0.99 (0.71, 1.39)	0.976
Drop of 3 points in FVC%Pred during interval	Yes (vs no)	1.16 (0.85, 1.59)	0.355	1.40 (0.99, 1.97)	0.058
Drop of 5 points in FVC%Pred during interval	Yes (vs no)	1.58 (1.12, 2.23)	0.009	1.70 (1.18, 2.46)	0.005
Drop of 10 points in FVC%Pred during interval	Yes (vs no)	2.62 (1.53, 4.49)	< 0.001	3.22 (1.87, 5.53)	< 0.001
Acute exacerbation during interval	Yes (vs no)	14.44 (7.31, 28.52)	< 0.001	3.47 (1.06, 11.38)	0.040
Age at baseline	For 5-year increment	1.08 (0.97, 1.21)	0.151	1.08 (0.96, 1.21)	0.222
Time since IPF diagnosis	For 1-year increment	1.01 (0.90, 1.14)	0.826	0.98 (0.86, 1.11)	0.733
Gender	Female (vs male)	1.27 (0.85, 1.92)	0.247	1.25 (0.81, 1.93)	0.320
Smoking status at baseline	Ex-smoker (vs never-smoker)	1.33 (0.89, 1.99)	0.159	1.38 (0.91, 2.09)	0.126
	Current smoker (vs never-smoker)	1.88 (0.99, 3.60)	0.056	2.35 (1.21, 4.57)	0.012
	Current smoker (vs others)	1.52 (0.86, 2.70)	0.148	1.85 (1.02, 3.35)	0.042
	Never-smoked (vs others)	0.73 (0.49, 1.09)	0.123	0.70 (0.46, 1.05)	0.083

FVC%Pred force vital capacity percent predicted; IPF idiopathic pulmonary fibrosis; vs versus

^aThis analysis was conducted on a subset of the primary analysis (total of 2767 observation) since we have no evidence for the interval before the 0–3 months