Table 1

Patients characteristics

TotalOther-SScSSc-emphysemaSSc-ILDSSc-CPFEP value
n (%)470 (100)202 (43)29 (6)196 (42)43 (9)
Age, mean (year)
(95% CI)
59.2
(57.2 to 60.5)
59.3
(57.3 to 61.3)
59.8
(54.8 to 64.9)
59.4
(57.4 to 61.3)
57.7
(53.3 to 62.1)
nss
Sex (M:F)90:38030:1728:2136:16016:27(CPFE vs SSc-ILD)**
(CPFE vs Other-SSc)***
Disease duration, mean (year) (95% CI)8.2
(7.4 to 8.9)
7.8
(6.6 to 9.0)
8.4
(5.3 to 11.5)
8.4
(7.4 to 9.5)
8.6
(6.1 to 11)
nss
Smoke habit‡ (none:former:current)351:57:52165:17:1917:5:6146:28:1825:7:9(CPFE vs Other-SSc)**
(SSc-Emphysema vs Other-SSc)*
ACA prevalence (n)16010721275(CPFE vs SSc-Other)§
(CPFE vs SSc-Emphysema)§
(SSc-ILD vs SSc-Emphysema)§
(SSc-Other vs SSc-Emphysema)*
(Other-SSc vs SSc-ILD)§
anti Scl70 prevalence (n)15423011318(CPFE vs SSc-Emphysema)***
(CPFE vs Other-SSc)§
(SSc-ILD vs SSc-Emphysema)§
(SSc-ILD vs Other-SSc)§
FVC-predicted, mean (95% CI)99%
(97 to 102)
109%
(105 to 113)
103%
(92 to 114)
91%
(88 to 95)
88%
(80 to 95)
(CPFE vs Other-SSc)†
(CPFE vs SSc-Emphysema)**
(Other-SSc vs SSc-ILD)†
(SSc-ILD vs SSc-Emphysema)*
TLC-predicted, mean (95% CI)93%
(90 to 95)
99%
(96 to 103)
104%
(93 to 116)
85%
(81 to 89)
82%
(76 to 88)
(CPFE vs Other-SSc)†
(CPFE vs SSc-Emphysema)†
(SSc-ILD vs SSc-Emphysema)†
(Other-SSc vs SSc-ILD)†
DLco-predicted, mean (95% CI)65%
(63 to 67)
73%
(70 to 75)
63%
(55 to 65)
61%
(58 to 64)
48%
(42 to 55)
(CPFE vs Other-SSc)†
(CPFE vs SSc-ILD)†
(CPFE vs SSc-Emphysema)**
(SSc-Other vs SSc-Emphysema)*
(Other-SSc vs SSc-ILD)***
DLco/VA-predicted, mean (95% CI)82%
(80 to 85)
85%
(81 to 88)
83%
(75 to 91)
85%
(81 to 89)
59%
(52 to 67)
(CPFE vs SSc-ILD)†
(CPFE vs Other-SSc)†
(CPFE vs SSc-Emphysema)†
ILD extent >20%, n (%)95 (20)0 (0)0 (0)74 (38)21 (49)(CPFE vs Other-SSc)§
(CPFE vs SSc-Emphysema)§
(SSc-ILD vs SSc-Emphysema)§
(Other-SSc vs SSc-ILD)§
sQCT of ILD, median (95% CI)1%
(0 to 3)
0015%
(13 to 17)
20%
(18 to 26)
(CPFE vs Other-SSc)†
(CPFE vs SSc-ILD)**
(CPFE vs SSc-Emphysema)†
(SSc-ILD vs SSc-Emphysema)†
(Other-SSc vs SSc-ILD)***
sQCT of emphysema, median (95% CI)004%
(2 to 10)
04%
(2 to 7)
(CPFE vs SSc-ILD)†
(CPFE vs Other-SSc)†
(SSc-Emphysema vs SSc-ILD)†
(SSc-Emphysema vs Other-SSc)†
  • A graphical presentation of key findings is in the online supplementary file 1.

  • *<0.05; **<0.01; ***<0.001.

  • †<0.005.

  • ‡Ten patients had an unknown smoke habit.

  • §<0.0001.

  • ACA, anticentromere antibodies; CPFE, combined pulmonary fibrosis and emphysema; DLco, diffusion lung capacity of CO; FVC, forced vital capacity; ILD, interstitial lung disease; IPF, Idiopathic pulmonary fibrosis; SSc, systemic sclerosis; TLC, Total lung capacity; VA, alveolar volume.