Table 3. Results from Cox proportional-hazards models for variables associated with symptom conversion to generalized myasthenia gravis.

	Univariate p	HR (95% CI)	Multivariate* p	HR (95% CI)
Sex	0.577	1.26 (0.56–2.84)
Age at onset	0.091	1.02 (0.99–1.05)
Titer of acetylcholine receptor antibody	<0.001	1.17 (1.08–1.28)	0.023	1.11 (1.02–1.22)
Thymoma	0.159	1.89 (0.78–4.54)
Prednisolone use before conversion	0.036	0.40 (0.17–0.94)	0.110
Abnormal repetitive nerve stimulation test†	0.002	4.34 (1.72–10.97)	0.022	3.13 (1.18–8.32)
Response decrease of 10–20%	0.351	1.50 (0.64–3.52)
Response decrease ≥20%	0.001	4.15 (1.84–9.36)
Response decrease ≥30%	<0.001	5.62 (2.31–13.67)

^*Variables with p<0.05 in the univariate model were entered into the multivariate model, ^†Decreased response in at least one of the five muscles.

CI: confidence interval, HR: hazard ratio.