Table 3.

Association between worsening of myasthenia gravis (MG) symptoms within one year since the first thymectomy and clinical and serological characteristics

	Model 1 (†)		Model 2 (‡)
	OR (95% CI)	P‐value (§)	OR (95% CI)	P‐value (§)
Sex	_	_	_	_
Males vs. females	0.97 (0.50–1.89)	0.94	0.65 (0.23–1.84)	0.42
Age at MG diagnosis (5‐unit increase)	0.94 (0.83–1.06)	0.30	0.97 (0.81–1.16)	0.73
MGFA status before thymectomy	_	0.007*	_	0.11
2B vs. no symptoms/2A	0.28 (0.12–0.66)	_	0.29 (0.07–1.11)	_
3/3A/4B/5 vs. no symptoms/2A	0.42 (0.19–0.92)	_	0.36 (0.11–1.16)	_
Masaoka‐Koga stage	_	0.78	_	0.21
IIb vs. I/IIa	1.07 (0.50–2.27)	_	2.05 (0.61–6.90)	_
III/IV vs. I/IIa	1.41 (0.54–3.69)	_	3.39 (0.86–13.34)	_
WHO classification of thymoma	_	0.78	_	_
B1 vs. AB	1.18 (0.47–2.99)	_	NA	NA
B1/B2 vs. AB	0.71 (0.30–1.71)	_	NA	_
B2/B3 vs. AB	0.96 (0.37–2.49)	_	NA	_
AChR‐Ab before thymectomy (nmol/L)	_	0.24	_	0.72
Tertile 2 vs. tertile 1	0.44 (0.13–1.44)	_	0.73 (0.21–2.55)	_
Tertile 3 vs. tertile 1	0.31 (0.07–1.36)	_	0.52 (0.10–2.62)	_
AChR‐Ab difference after minus before thymectomy (nmol/L)	_	0.90	_	0.85
Tertile 2 vs. tertile 1	0.73 (0.19–2.88)	_	1.01 (0.22–4.64)	_
Tertile 3 vs. tertile 1	0.85 (0.20–3.58)	_	1.39 (0.29–6.68)	_

^† Model 1, unadjusted estimates except for AChR‐Ab before thymectomy and AChR‐Ab difference after versus before thymectomy, that are adjusted one for each other. Analyses conducted on the individuals without missing values in the corresponding predictor.

^‡ Model 2, estimates adjusted for all the variables in the table except for the WHO classification of thymoma. Analyses conducted on 133 individuals without missing values in any predictor.

^§ Wald test.

AChR‐Ab, acetylcholine receptor antibody; CI, confidence interval; MG, myasthenia gravis; MGFA, Myasthenia Gravis Foundation of America; NA: not applicable; OR, odds ratio; WHO, World Health Organization score.

*statistically significant.