Association between patient characteristics and SRC development. Longitudinal data analysis using GEE with target variable “SRC,” including all visits (univariable analysis).
| Variable | Univariable GEE | ||
|---|---|---|---|
| p | OR | 95% CI | |
| Age at disease onset | 0.734 | 1.003 | 0.986–1.020 |
| Disease duration, yrs | 0.447 | 0.985 | 0.949–1.023 |
| Disease duration ≤ 5 yrs | 0.267 | 1.294 | 0.821–2.038 |
| Sex, male vs female | 0.063 | 0.502 | 0.243–1.038 |
| BMI | 0.162 | 0.958 | 0.902–1.017 |
| Diagnosis | 0.004 | ||
| Overlap vs lcSSc | 0.848 | 1.087 | 0.463–2.554 |
| DcSSc vs lcSSc | 0.002 | 2.545 | 1.424–4.549 |
| ANA | 0.922 | 0.958 | 0.406–2.262 |
| Anti-Scl 70 | 0.879 | 0.944 | 0.450–1.980 |
| ACA | 0.014 | 0.459 | 0.248–0.853 |
| Anti-RNAP | < 0.001 | 7.298 | 3.181–16.743 |
| mRSS, total score | 0.001 | 1.043 | 1.019–1.069 |
| mRSS > 10 | 0.008 | 1.934 | 1.186–3.153 |
| mRSS > 15 | 0.023 | 2.058 | 1.104–3.836 |
| mRSS > 20 | 0.066 | 1.865 | 0.959–3.628 |
| DLCO ≤ 75% | < 0.001 | 4.419 | 2.018–9.674 |
| Elevated ESR | 0.004 | 2.500 | 1.349–4.633 |
| Digital ulceration | 0.414 | 1.238 | 0.742–2.064 |
| CK elevation | 0.020 | 2.247 | 1.134–4.452 |
| Tendon friction rubs | 0.158 | 1.885 | 0.782–4.541 |
| PAH | 0.004 | 2.082 | 1.263–3.430 |
| Lung fibrosis | 0.066 | 1.609 | 0.969–2.670 |
| GI involvement | 0.070 | 1.767 | 0.955–3.269 |
SRC: scleroderma renal crisis; GEE: generalized estimating equations; BMI: body mass index; lcSSc: limited cutaneous systemic sclerosis; dcSSc: diffuse cutaneous systemic sclerosis; ANA: antinuclear antibody; ACA: anticentromere antibodies; anti-RNAP: anti-RNA polymerase antibodies; mRSS: modified Rodnan skin score; ESR: erythrocyte sedimentation rate; CK: creatine kinase; PAH: pulmonary arterial hypertension; GI: gastrointestinal.