Table 4.
Univariate and multivariate Cox regression analysis of second 3 point decrease of QMGS
| Parameters | Univariate | Multivariate | ||
|---|---|---|---|---|
| HR (95% CI) | P | HR (95% CI) | P | |
| Sex | ||||
| Male | Ref. | – | ||
| Female | 1.11 (0.87 to 1.41) | 0.398 | ||
| Age, years | ||||
| < 42 | Ref. | – | Ref. | – |
| ≥ 42 | 0.52 (0.40 to 0.66) | < 0.001 | 0.53 (0.41 to 0.68) | < 0.001 |
| Disease course, months | ||||
| < 8 | Ref. | – | ||
| ≥ 8 | 0.85 (0.67 to 1.07) | 0.164 | ||
| Preoperative steroids | ||||
| No | ref | – | ||
| Yes | 0.94 (0.74 to 1.20) | 0.622 | ||
| MGFA class | ||||
| I + IIA | Ref. | – | Ref. | – |
| IIB–V | 0.74 (0.57 to 0.96) | 0.025 | 0.79 (0.61 to 1.03) | 0.087 |
| Surgical approach | ||||
| Sternotomy | Ref. | – | ||
| VATS | 1.12 (0.75 to 1.67) | 0.577 | ||
| Masaoka-Koga stage | ||||
| I | Ref. | – | Ref. | – |
| IIa–IIIa | 0.51 (0.32 to 0.80) | 0.004 | 0.53 (0.33 to 0.84) | 0.007 |
| WHO pathologic type | ||||
| A + AB | Ref. | – | ||
| B1–B3 | 1.23 (0.87 to 1.74) | 0.237 | ||
| Tumor size | ||||
| ≤ 5 cm | Ref. | – | Ref. | – |
| > 5 cm | 0.67 (0.45 to 0.98) | 0.042 | 0.92 (0.61 to 1.39) | 0.705 |
| Complete resection | ||||
| No | Ref. | – | Ref. | – |
| Yes | 22.08 (2.03 to 240.48) | 0.011 | Failed estimationa | – |
aFailed estimation was due to insufficient number of cases
CI, confidence interval; HR, hazard ratio; MGFA, Myasthenia Gravis Foundation of America; QMGS, Quantitative Myasthenia Gravis Score; VATS, video-assisted thoracoscopic surgery;WHO, World Health Organization