Table 2.

Characteristics Associated With Oral Treponema pallidum qPCR Positivity in Men With Early Syphilis: Univariable Logistic Regression Analysis

Characteristic	Unadjusted OR (95% CI)	P Value	AIC	R 2,a %	C-Statistic, %
Age, y		.02	39	38	78
18–29	22.50 (1.61–314.48)	.02
30–39	1.82 (.16–20.71)	.63
40+	Ref
Syphilis stage		.27	47	13	66
Primary	Ref
Secondary	4.00 (.39–41.5)	.25
Early latent	8.33 (.63–110.0)	.11
RPR titer		.85	50	1	54
<1:32	Ref
1:32–1:64	1.67 (.21–13.22)	.63
>1:64	1.75 (.24–12.64)	.58
PWHb			42	15	15
Yes	0.09 (.01–2.95)	.18
No	Ref
CD4 count, cells/mm3		.36	40	11	65
<200	Ref
200–349	0.13 (.01–2.18)	.16
≥350	0.36 (.05–2.82)	.33

P value in bold indicates overall association of a variable using type 3 analysis of effects (Wald χ²) for variables with >2 categories.

Abbreviations: AIC, Akaike information criterion; CI, confidence interval; OR, odds ratio; PCR, polymerase chain reaction; Ref, reference category.

^aNagelkerke's max-rescaled R² reported in PROC LOGISTIC procedure of SAS.

^bFirth bias correction used due to zero cell leading to quasi-complete separation.