Table 8.

Univariate analysis to identify factors associated with physician visits 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	1.05 (1.00, 1.10)	0.040	1.04 (0.99, 1.10)	0.141
Change in FVC%Pred over interval	For 10-unit decrement	1.13 (1.00, 1.28)	0.042	0.93 (0.81, 1.06)	0.293
Any drop in FVC%Pred during interval	Yes (vs no)	1.10 (0.95, 1.26)	0.197	0.90 (0.77, 1.05)	0.178
Drop of 3 points in FVC%Pred during interval	Yes (vs no)	1.14 (0.98, 1.32)	0.096	1.07 (0.90, 1.28)	0.433
Drop of 5 points in FVC%Pred during interval	Yes (vs no)	1.23 (1.03, 1.46)	0.020	1.05 (0.85, 1.30)	0.638
Drop of 10 points in FVC%Pred during interval	Yes (vs no)	1.26 (0.90, 1.75)	0.175	0.88 (0.58, 1.32)	0.526
Acute exacerbation during interval	Yes (vs no)	1.75 (0.91, 3.37)	0.094	0.95 (0.36, 2.53)	0.924
Age at baseline	For 5-year increment	1.07 (1.01, 1.14)	0.028	1.07 (0.99, 1.14)	0.070
Time since IPF diagnosis	For 1-year increment	1.04 (0.97, 1.12)	0.244	1.03 (0.95, 1.12)	0.427
Gender	Female (vs male)	1.32 (1.05, 1.67)	0.017	1.29 (1.00, 1.67)	0.047
Smoking status at baseline	Ex-smoker (vs never-smoker)	0.96 (0.77, 1.19)	0.692	0.91 (0.72, 1.16)	0.450
	Current smoker (vs never-smoker)	0.94 (0.59, 1.50)	0.809	0.85 (0.49, 1.46)	0.545
	Current smoker (vs others)	0.97 (0.63, 1.51)	0.904	0.90 (0.54, 1.51)	0.693
	Never-smoked (vs others)	1.04 (0.85, 1.29)	0.684	1.10 (0.87, 1.39)	0.424

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