Table 2. Performance of the HCV-MOSAIC risk score among HIV-infected men who have sex with men in the development and three validation studies.

	Development study	Validation studies
	MOSAIC study, the Netherlands	Case–control study, Belgium	Case–control study, UK	Dutch STI clinic surveys
Sensitivity (95% CI)	78.0% (67.9–85.6)	73.1% (59.7–83.2)	93.3% (84.1–97.4)	100% (72.2–100)
Specificity (95% CI)	78.6% (70.8–84.8)	65.6% (55.3–74.6)	56.2% (47.6–64.4)	60.6% (54.7–66.2)
Proportion to be testeda	43%	49%	59%	42%
Area under the ROC curve (95% CI)	0.82 (0.76–0.88)	0.74 (0.66–0.83)	0.82 (0.76–0.88)	0.92 (0.85–0.98)

CI: confidence intervals; HCV: hepatitis C virus; MOSAIC: MSM (men who have sex with men) Observational Study of Acute Infection with hepatitis C; ROC: receiver operating characteristic; STI: sexually transmitted infection; UK: United Kingdom.

^a Proportion of all cases and controls with a risk score of ≥ 2.0.