Cox regression analyses of risk of CTD in patients with primary ITP
| Variable | Univariate analysis | Multivariate analysis | ||
| HR (95% CI) | P value | HR (95% CI) | P value | |
| Age | 1.00 (0.98 to 1.02) | 0.940 | 1.00 (0.98 to 1.03) | 0.843 |
| Female | 0.74 (0.33 to 1.69) | 0.477 | 0.55 (0.22 to 1.35) | 0.190 |
| White cell count | 0.92 (0.81 to 1.05) | 0.212 | – | – |
| Lymphocytes | 0.94 (0.82 to 1.09) | 0.425 | – | – |
| Haemoglobin | 1.00 (0.98 to 1.01) | 0.623 | – | – |
| Platelet count | 1.00 (0.99 to 1.01) | 0.741 | – | – |
| ANA positivity | 8.77 (3.97 to 19.40) | <0.001 | 6.15 (2.66 to 14.23) | <0.001 |
| ENA positivity | 6.55 (3.00 to 14.32) | <0.001 | 3.97 (1.75 to 9.04) | 0.001 |
| Anti-SSA positivity | 7.04 (3.29 to 15.06) | <0.001 | 3.43 (1.49 to 7.86)* | 0.004 |
| Anti-Ro52 positivity | 4.15 (1.86 to 9.26) | <0.001 | – | – |
| Anti-SSB positivity | 7.06 (0.95 to 52.66) | 0.056 | 1.49 (0.18 to 12.51)† | 0.713 |
| C3 | 0.10 (0.02 to 0.69) | 0.019 | 0.27 (0.04 to 1.83) | 0.180 |
| C4 | 0.0093 (0.000047 to 1.85) | 0.083 | – | – |
| IgA | 0.94 (0.59 to 1.50) | 0.796 | – | – |
| IgG | 1.07 (0.99 to 1.15) | 0.076 | – | – |
| IgM | 0.67 (0.35 to 1.30) | 0.239 | – | – |
*Outcome for anti-SSA was adjusted for ANA, C3, anti-SSB, age and gender.
†Outcome for anti-SSB was adjusted for ANA, C3, anti-SSA, age and gender.
Anti-SSA, anti-Sjogren’s syndrome A antibody; anti-SSB, anti-Sjogren’s syndrome B antibody; ENA, extractable nuclear antigen antibodies.