Table 2.

Univariate and multivariate logistic regression analysis of RP-ILD in IIM-ILD patients.

Factors	Before propensity score matching			After propensity score matching
	P-value	OR value	95%Cl	P-value	OR value	95% Cl
Univariate analysis
Age (y)	0.626	1.009	0.973~1.046	0.248	1.024	0.983~1.067
Sex (male/female)	0.851	1.083	0.469~2.500	0.525	1.345	0.540~3.347
Clinical manifestations or comorbidities
Dysphagia	0.420	0.588	0.162~2.133	0.514	0.594	0.125~2.831
Dysarthria	0.456	0.448	0.055~3.688	0.999	<0.001	0.000~
Respiratory muscle involvement	0.963	1.054	0.113~9.795	0.999	<0.001	0.000~
Cardiac involvement	0.625	0.587	0.069~4.965	0.714	0.667	0.076~5.814
Gastrointestinal hemorrhage	0.999	<0.001	0.000~	0.999	<0.001	0.000~
Pulmonary bacterial infection	0.168	1.852	0.770~4.451	0.875	1.087	0.386~3.061
Pulmonary fungal infection	0.963	1.054	0.113~9.795	0.555	2.087	0.181~24.020
Carcinoma	0.825	1.129	0.383~3.328	0.431	1.579	0.507~4.918
UIP pattern	0.724	1.195	0.444~3.218	0.790	0.868	0.307~2.454
Pneumomediastinum	0.123	3.404	0.718~16.134	0.985	1.022	0.109~9.581
Disease activity
MYOACT score	<0.001	1.336	1.167~1.530	<0.001	1.316	1.138~1.522
Lung function testing
FVC% (%)	0.600	0.994	0.972~1.017	0.766	1.004	0.979~1.029
TLC (L)	0.057	0.668	0.442~1.012	0.157	0.720	0.457~1.135
FEV1% (%)	0.074	0.979	0.957~1.002	0.315	0.987	0.963~1.012
FEV1/FVC	0.240	0.086	0.001~5.171	0.123	0.014	0.000~3.162
DLCO% (%)	0.003	0.964	0.941~0.987	0.010	0.964	0.937~0.991
Myositis-specific antibodies and myositis-associated antibodies
Anti-MDA5	0.009	3.209	1.343~7.668	0.009	3.518	1.366~9.064
Anti-PL-7	0.687	0.764	0.207~2.821	0.514	0.594	0.125~2.831
Anti-PL-12	0.250	2.938	0.468~18.452	0.152	4.364	0.582~32.697
Anti-EJ	0.278	2.231	0.523~9.507	0.546	1.691	0.308~9.297
Anti-Ro-52	0.499	1.327	0.584~3.012	0.775	1.141	0.462~2.817
Anti-Jo-1	0.588	0.727	0.230~2.301	0.331	0.524	0.142~1.927
Anti-OJ	0.999	<0.001	0.000~	0.999	<0.001	0.000~
Anti-TIF1γ	0.626	0.679	0.143~3.215	0.783	0.800	0.163~3.917
Anti-Ku	0.736	0.690	0.080~5.968	0.985	1.022	0.109~9.581
Anti-SRP	0.999	<0.001	0.000~	0.999	<0.001	0.000~
Anti-NXP2	0.999	<0.001	0.000~	0.999	<0.001	0.000~
Anti-PM-Scl75	0.205	2.280	0.637~8.167	0.066	3.720	0.917~15.096
Anti-PM-Scl100	0.999	<0.001	0.000~	0.999	<0.001	0.000~
Anti-Mi-2α	0.532	0.509	0.061~4.238	0.999	<0.001	0.000~
Anti-Mi-2β	0.670	1.432	0.274~7.488	0.786	1.377	0.137~13.850
Anti-SAE1	0.999	<0.001	0.000~	0.999	<0.001	0.000~
Comorbidities/harmful hobbies
Smoking	0.895	0.924	0.287~2.973	0.768	1.200	0.357~4.038
Alcohol abuse	0.694	0.808	0.280~2.331	0.782	1.170	0.385~3.549
Hypertension	0.657	0.770	0.242~2.444	0.760	0.832	0.254~2.719
Diabetes	0.583	1.330	0.481~3.683	0.393	1.588	0.549~4.592
Hepatitis	0.507	1.414	0.508~3.934	0.691	1.254	0.411~3.825
Allergic History	0.181	0.356	0.079~1.615	0.999	<0.001	0.000~
Therapies
Steroid monotherapy	0.411	1.001	0.999~1.004	0.555	1.001	0.998~1.003
Steroid + DMARDs	0.167	0.561	0.247~1.274	0.026	0.345	0.135~0.882
Steroid + IVIG	0.015	3.492	1.273~9.579	0.002	5.625	1.845~17.153
Steroid + DMARDs + IVIG	0.961	0.967	0.257~3.644	0.783	0.800	0.163~3.917
Maximum dosage of steroida	0.363	1.001	0.998~1.005	0.527	1.001	0.998~1.004
Nintedanib	0.030	0.192	0.043~0.851	0.025	0.179	0.040~0.808
IIM subtypes
DM	0.143	0.542	0.239~1.231	0.313	0.628	0.254~1.551
PM	0.658	0.800	0.298~2.150	0.185	0.417	0.115~1.519
ADM	0.010	3.844	1.382~10.695	0.004	4.944	1.661~14.721
Multivariate analysis
MYOACT score	<0.001	1.346	1.151~1.574	<0.001	1.392	1.175~1.650
DLCO%	0.036	0.970	0.943~0.998
Nintedanib	0.004	0.072	0.012~0.426	0.009	0.093	0.016~0.549
ADM	0.012	5.192	1.433~18.808	0.003	7.343	2.007~26.865

RP-ILD, Rapidly progressive interstitial lung disease; IIM-ILD, Idiopathic-inflammatory-myopathy-related interstitial lung disease; y, years; m, months; UIP pattern, Usual interstitial pneumonia pattern; MYOACT, Myositis Disease Activity Assessment Visual Analog Scales; FVC%, Percent-predicted forced vital capacity; TLC, Total lung capacity; L, Liter; FEV1%, Percent-predicted forced expiratory volume in 1 s; FEV1/FVC, Ratio of FEV1 over FVC; DLCO%, Percent-predicted diffusing capacity of the lung for carbon monoxide; DMARDs, Disease-modifying anti-rheumatic drugs; IVIG, Intravenous immunoglobulin; IIM, Idiopathic inflammatory myopathy; DM, dermatomyositis; PM, Polymyositis; ADM, Amyopathic dermatomyositis.

^aCalculated by prednisolone.