Risk factor | Incident gangrene n/N (%) | No incident gangrene, n/N (%) | OR (95% CI) | p Value* |
---|---|---|---|---|
(A) ULR (N=3809)† | N=243 | N=3566 | ||
Female gender | 189/243 (77.8) | 2938/3566 (82.4) | 0.73 (0.53 to 1.01) | 0.055 |
Smoking status | ||||
Current | 45/205 (22.0) | 438/3102 (14.1) | 1.91 (1.32 to 2.76) | <0.001 |
Former | 58/205 (28.3) | 728/3102 (23.5) | 1.46 (1.04 to 2.04) | 0.028 |
Number of finger DUs at enrolment | ||||
1–2 | 89/236 (37.7) | 1315/3546 (37.1) | 1.27 (0.93 to 1.72) | 0.132 |
3+ | 58/236 (24.6) | 666/3546 (18.8) | 1.54 (1.09 to 2.17) | 0.015 |
Anti-Scl 70 | 103/196 (52.6) | 1279/2872 (44.5) | 1.39 (1.04 to 1.87) | 0.027 |
Previous gangrene | 96/229 (41.9) | 404/3378 (12.0) | 4.75 (3.57 to 6.34) | <0.0001 |
Previous autoamputation | 32/231 (13.9) | 188/3386 (5.6) | 2.69 (1.78 to 4.04) | <0.0001 |
Previous soft-tissue infection requiring systemic antibiotics | 94/222 (42.3) | 933/3253 (28.7) | 1.76 (1.33 to 2.32) | <0.0001 |
Previous osteomyelitis | 19/232 (8.2) | 84/3367 (2.5) | 3.24 (1.19 to 5.47) | <0.0001 |
Ongoing autoamputation | 6/242 (2.5) | 46/3552 (1.3) | 2.32 (0.97 to 5.57) | 0.059 |
Ongoing osteomyelitis | 4/243 (1.6) | 24/3558 (0.7) | 2.36 (0.80 to 6.99) | 0.121 |
Previous hospitalisation(s) for DUs (at least 1 day) | 144/231 (62.3) | 1290/3385 (38.1) | 2.49 (1.89 to 3.29) | <0.0001 |
Previous upper limb sympathectomy | 20/228 (8.8) | 100/3345 (3.0) | 3.24 (1.94 to 5.40) | <0.0001 |
Previous digital sympathectomy | 11/228 (4.8) | 58/3341 (1.7) | 2.70 (1.38 to 5.31) | 0.004 |
Previous arterial reconstruction | 5/227 (2.2) | 21/3336 (0.6) | 3.43 (1.25 to 9.44) | 0.017 |
Not employed/self-employed | 205/243 (84.4) | 2687/3566 (75.4) | 1.78 (1.22 to 2.61) | 0.003 |
(B) MLR‡(N=2479) | N=157 | N=2322 | ||
Observation time, mean (SD), weeks | 174.7 (78.7) | 126.2 (78.9) | 1.03 (1.02 to 1.04) | <0.0001 |
Smoking status | ||||
Current | 27/157 (17.2) | 311/2322 (13.4) | 1.72 (1.07 to 2.77) | 0.025 |
Former | 47/157 (29.9) | 509/2322 (21.9) | 1.69 (1.14 to 2.51) | 0.009 |
Number of finger DUs at enrolment | ||||
1–2 | 60/157 (38.2) | 951/2322 (41.0) | 1.35 (0.90 to 2.03) | 0.144 |
3+ | 46/157 (29.3) | 491/2322 (21.1) | 1.69 (1.09 to 2.62) | 0.020 |
Anti-Scl 70 | 79/157 (50.3) | 1031/2322 (44.4) | 1.39 (0.99 to 1.96) | 0.058 |
Previous gangrene | 63/157 (40.1) | 244/2322 (10.5) | 4.67 (3.24 to 6.73) | <0.0001 |
Previous upper limb sympathectomy | 15/157 (9.6) | 67/2322 (2.9) | 2.21 (1.15 to 4.27) | 0.018 |
*Wald χ2 test.
†For the ULR analysis, observation time was a fixed covariate in the model. Data are shown for variables having p<0.15 and n>3000 for the patients for whom information is available).
‡For the MLR analysis, observation time was forced into the model as a fixed covariate and not included by the forward selection procedure; variables were selected with a selection criterion of p=0.15. Data are shown for the subset of patients making up the final models (n=2479) to allow comparison with the full cohort.
ACA, anticentromere antibody; ANA, antinuclear antibody; DU, digital ulcer; MLR, multivariable logistic regression; PAH, pulmonary arterial hypertension; RNP, ribonucleic protein; ULR, univariable logistic regression.