Table 4 .

Performance characteristics of RPR tests for diagnosis of syphilis

Non-treponemal tests		TPPA
		Positive	Negative
HBI HiSens Auto RPR	Positive	31	3
	Negative	28	50
Sensitivity		52.5%	(95% CI 39.1% to 65.7%)
Specificity		94.3%	(95% CI 84.3% to 98.8%)
Positive predictive value		91.2%	(95% CI 76.3% to 98%)
Negative predictive value		64.1%	(95% CI 52.4% to 74.7%)
		TPPA
		Positive	Negative
BD Macro-Vue RPR card	Positive	51	3
	Negative	8	50
Sensitivity		86.4%	(95% CI 75% to 93.9%)
Specificity		94.3%	(95% CI 84.3% to 98.8%)
Positive predictive value		94.4%	(95% CI 84.6% to 98.8%)
Negative predictive value		86.2%	(95% CI 74.6% to 93.8%)

RPR, rapid plasma reagin; TPPA, Treponema pallidum particle agglutination.