Introduction
Methods
Design and study population
Population and outcomes
Parameters | dcSSc with no HAQ-DI score at any time N = 4132 | dcSSc with ≥ 1 HAQ-DI score N = 690 | dcSSc with ≥ 2 HAQ-DI scores N = 424 |
---|---|---|---|
Age (years) | |||
Mean (SD) | 52.2 (13.6) | 53.8 (12.9) | 53.1 (12.7) |
IQR | 42.6–62.4 | 45.6–62.6 | 43.9–62.3 |
Age (years) at onset of RP, N | 3953 | 677 | 414 |
Mean (SD) | 43.3 (14.7) | 42.4 (14.4) | 42.5 (14.3) |
IQR | 32.7–54.0 | 32.4–52.0 | 32.1–52.3 |
Female, n (%) | 3214 (77.8%) | 537 (77.8%) | 320 (75.5%) |
Disease duration, n (%) | |||
≤ 18 months | 962 (23.3%) | 60 (8.7%) | 39 (9.2%) |
> 18 months | 3170 (76.7%) | 630 (91.3%) | 385 (90.8%) |
Current digital ulcers, n (%) | |||
Yes | 1493 (36.6%) | 120 (18.3%) | 70 (17.3%) |
No | 2585 (63.4%) | 535 (81.7%) | 335 (82.7%) |
Puffy fingers, n (%) | |||
Yes | 972 (48.7%) | 216 (35.5%) | 148 (39.1%) |
No | 1024 (51.3%) | 392 (64.5%) | 231 (60.9%) |
mRSS, N | 3895 | 656 | 403 |
Mean (SD) | 16.4 (9.9) | 11.7 (9.0) | 11.8 (8.6) |
IQR | 9.0–23.0 | 5.0–17.0 | 5.0–17.0 |
HAQ-DI score | |||
Mean (SD) | NA | 1.0 (0.8) | 1.1 (0.8) |
IQR | NA | 0.4–1.6 | 0.4–1.8 |
Advanced organ involvement, n (%) | |||
None | 3448 (83.7%) | 468 (68.8%) | 295 (69.9%) |
One | 585 (14.2%) | 178 (26.2%) | 108 (25.6%) |
Multiple | 86 (2.1%) | 34 (5.0%) | 19 (4.5%) |
Missing | 13 | 10 | 2 |
Statistical analyses
Regression analyses to identify predictors of death and HAQ-DI score progression
Transition model for dcSSc
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HAQ-DI state in t = f(age in t − 1, sex, lung status in t − 1)
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Lung status in t = f(HAQ-DI state in t − 1, time since disease onset)
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Mortality in t = f(lung status in t − 1, age in t − 1, sex) where t = time (years); f = “is function of”.
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HAQ-DI state after 1 year = f(age at baseline, sex, lung status at baseline)
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Lung status in year t = f(HAQ-DI state at baseline, time since disease onset)
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Mortality in t = f(lung status in t − 1, age in t − 1, sex)
Results
Study population
Predictors of death
Baseline parameter | HR | 95% CI for HR | p value |
---|---|---|---|
Male gender | 1.15 | 0.57, 2.35 | 0.698 |
HAQ-DI score | 3.01 | 1.98, 4.60 | < 0.001 |
Age at onset of RP | 1.03 | 1.00, 1.05 | 0.030 |
mRSS | 1.02 | 0.99, 1.05 | 0.303 |
RNA polymerase III positive | 0.04 | 0.00, 11.11 | 0.260 |
Anti-topoisomerase I antibody | 0.92 | 0.45, 1.88 | 0.817 |
Immunomodulator treatment | 0.86 | 0.45, 1.63 | 0.638 |
Corticosteroids > 10 mg/day | 6.29 | 2.64, 14.98 | < 0.001 |
One advanced organ involvement | 3.93 | 1.99, 7.78 | < 0.001 |
Two advanced organ involvement | 8.43 | 3.40, 20.91 | < 0.001 |
Advanced lung involvement | 4.81 | 2.37, 9.77 | < 0.001 |
Advanced cardiac involvement | 6.24 | 1.47, 26.50 | 0.013 |
Advanced GI involvement | 2.22 | 1.06, 4.64 | 0.035 |
Advanced PH involvement | 6.50 | 2.66, 15.88 | < 0.001 |
Advanced renal involvement | 1.12 | 0.15, 8.13 | 0.914 |
Baseline parameter | HR | 95% CI for HR | p value |
---|---|---|---|
HAQ-DI score | 2.69 | 1.71, 4.23 | < 0.001 |
Age at onset of RP | 1.02 | 0.99, 1.04 | 0.177 |
mRSS | 1.01 | 0.98, 1.04 | 0.527 |
Male gender | 1.06 | 0.48, 2.35 | 0.888 |
Immunomodulator treatment | 0.41 | 0.20, 0.84 | 0.014 |
Corticosteroids > 10 mg/day | 5.41 | 2.10, 13.97 | < 0.001 |
Advanced organ involvement (reference: no organ involvement) | |||
One | 3.57 | 1.77, 7.18 | < 0.001 |
Multiple | 4.81 | 1.73, 13.34 | 0.003 |
Predictors of HAQ-DI score progression
B | 95% CI for B | p value | |
---|---|---|---|
Constant | − 0.16 | − 0.51, 0.20 | 0.389 |
HAQ-DI score at baseline | − 0.15 | − 0.27, − 0.04 | 0.009 |
Age at onset of RP | − 0.002 | − 0.01, 0.004 | 0.518 |
Male gender | 0.02 | − 0.18, 0.22 | 0.834 |
mRSS | 0.01 | 0.0001, 0.03 | 0.048 |
Immunomodulator treatment | 0.02 | − 0.17, 0.20 | 0.870 |
Corticosteroids > 10 mg/day | 0.12 | − 0.77, 1.01 | 0.791 |
Advanced organ involvementa | − 0.15 | − 0.67, 0.37 | 0.575 |
Advanced lung involvement | 0.05 | − 0.55, 0.65 | 0.866 |
Advanced cardiac involvement | 0.62 | − 0.36, 1.60 | 0.213 |
Advanced GI involvementb | 0.40 | − 0.20, 0.99 | 0.186 |
Advanced renal involvement | 0.47 | − 0.56, 1.50 | 0.367 |
Esophageal symptoms | 0.33 | 0.14, 0.52 | 0.001 |
Stomach symptoms | − 0.04 | − 0.25, 0.16 | 0.670 |
Intestinal symptoms | 0.09 | − 0.09, 0.26 | 0.335 |