Stratified Threshold Values of QuantiFERON Assay for Diagnosing Tuberculosis Infection in Immunocompromised Populations

Table 3

Analysis of area under the receiver operating characteristic curves for lymphocyte-stratified patients groups.

Lymphocyte count/mm^3	n	AUROC curve	95% CI	SE	cutoff value IU/mL	sensitivity %	95% CI	specificity %	95% CI
<300	45	0.86	0.777–0.943	0.04	0.04	80	65.4–90.4	86	81.7–89.2
300–500	57	0.82	0.806–0.938	0.03	0.04	79	66.1–88.6	86	81.7–89.2
500–700	79	0.93^a	0.883–0.973	0.02	0.05	89	81.0–95.5	89	85.7–92.4
700–1000	145	0.97^b	0.962–0.987	0.01	0.1	87	80.3–91.9	94	91.2–96.3
1000–1200	98	0.98^b	0.957–0.994	0.01	0.1	91	83.3–95.7	94	91.2–96.3
1200–1500	121	0.97^b	0.954–0.993	0.01	0.1	93	87.4–97.1	95	91.8–96.8
1500–1800	78	0.97^b	0.949–0.989	0.01	0.15	91	82.4–96.3	96	93.2–97.6
>1800	104	0.99^b	0.992–0.9997	0.002	0.19	96	90.4–98.9	98	96.0–99.2

Note. AUROC: area under the receiver operating characteristic; SE: standard error; CI: Confidence Interval Categories for lymphocyte counts exclude the value shown for the upper end of the range.
^a: 𝑃<.05 versus <300/mm³ category and 𝑃<.05 versus 300–500/mm³ category.
^b: 𝑃<.05 versus <300/mm³ category, 𝑃<.05 versus 300–500/mm³ category, and 𝑃<.05 versus 500–700/mm³ category.