Performance of Clinical Algorithms for Smear-Negative Tuberculosis in HIV-Infected Persons in Ho Chi Minh City, Vietnam

Table 2

Performance of different algorithms in screening TB for 390 HIV-infected patients having sputum smear negative to AFB.

Combination of predictors	Sensitivity	Specificity	PPV	NPV	LR+	LR−	Area under ROC curve*
Combination of three clinical predictors
Cough or fever or night sweats	8/22 (36)	266/368 (72)	8/102 (7)	266/280 (95)	1.31	0.88	0.54
Cough or night sweat or weight loss	9/22 (41)	236/368 (64)	9/141 (6)	236/249 (95)	1.14	0.92	0.52
Fever or night sweats or weight loss	8/22 (36)	285/368 (78)	8/91 (9)	285/299 (95)	1.61	0.82	0.57
Combination of four clinical predictors
Cough or fever or night sweats or weight loss	10/22 (46)	235/368 (64)	10/143 (7)	235/247 (95)	1.25	0.85	0.55
Combination of four clinical predictors and TST
Symptoms or TST	22/22 (100)	89/368 (24)	22/301 (7)	89/89 (100)	1.32	0	0.62

*ROC curve: receiver operating characteristic curve.
PPV: positive predictive value. NPV: negative predictive value.
LR+: positive likelihood ratio, calculated by sensitivity ÷ (1 − specificity).
LR−: negative likelihood ratio calculated by (1 − sensitivity) ÷ specificity [18].
Sensitivity, specificity, PPV, and NPV are reported as proportion (%).
CXR: chest radiography.
Cough: lasting ≥2 weeks in the past 4 weeks.
Fever: lasting ≥2 weeks in the past 4 weeks.
Night sweats: lasting ≥2 weeks in the past 4 weeks.
Weight loss: lasting ≥2 weeks in the past 4 weeks.