Table 2: Comparison of clinical characteristics among CTD-ILD, UCTD-ILD, and IPF patients.

CTD-ILD UCTD-ILDIPFP1 P2 P3

Subject (n)636575
Age (years) 0.05 0.050.614
Sex (M/F)20/4341/2452/230.0000.0000.434
Ever smoker n (%)15 (24)35 (54)35 (47)0.0000.0050.397
Symptoms n (%)
 Cough45 (71)65 (100)67 (89)0.0000.0070.007
 Sputum33 (52)51 (78)48 (64)0.0020.1670.061
 Dyspnea35 (56)49 (75)57 (76)0.0180.0110.933
 Fatigue21 (33)27 (42)27 (36)0.3380.7430.502
 Hemoptysis0 (0)5 (8)4 (5)0.0740.1770.824
 Chest discomfort0 (0)8 (12)16 (21)0.0040.0000.158
 Chest pain0 (0)11 (17)13 (17)0.0010.0010.949
 Skin rash14 (22)16 (25)0 (0)0.7490.0000.000
 Arthralgia19 (30)14 (19)1 (1)0.2650.0000.000
 Dry eyes/dry mouth5 (8)7 (11)0 (0)0.5830.0430.012
 Raynaud’s phenomenon9 (14)10 (15)0 (0)0.8610.0020.001
 Proximal muscle weakness8 (13)0 (0)0 (0)0.0080.004
 Muscle pain13 (21)0 (0)0 (0)0.0000.000
 Recurrent unexplained fever4 (6)9 (14)7 (9)0.1600.5190.403
 Leg/foot swelling4 (6)6 (9)10 (13)0.7810.1760.447
 Face swelling2 (3)0 (0)0 (0)0.4620.401
 Oral ulceration2 (3)0 (0)0 (0)0.4620.401

P1: Possibility when comparing CTD-ILD group and UCTD-ILD group. P2: Possibility when comparing CTD-ILD group and IPF group. P3: Possibility when comparing UCTD-ILD group and IPF group.