Table 3.

Cox regression analysis for the incidence of acute exacerbation in idiopathic pulmonary fibrosis (IPF) and non-IPF idiopathic interstitial pneumonia (IIP) patients according to baseline characteristics after stepwise selection

Characteristic	HR	95% CI	P value
IPF
FVC	1.23	1.07 to 1.42	0.005
mMRC score	1.56	1.22 to 2.00	<0.0001
Non-IPF IIPs
mMRC score	2.04	1.54 to 2.71	<0.0001
log10(CRP)	1.88	1.10 to 3.20	0.021

CRP, C reactive protein; FVC, forced vital capacity; mMRC, modified Medical Research Council.