Table 3.

Diagnostic Accuracy of Sputum Tests and C-Reactive Protein in 207 Adult Participants With HIV and Symptoms Suggestive of Tuberculosis

Index Test	Sensitivity (95% CI)	Specificity (95% CI)	Positive Predictive Value (95% CI)	Negative Predictive Value (95% CI)	Likelihood Ratio +ve (95% CI)	Likelihood Ratio –ve (95% CI)
Smear (including scanty)	0.12 (0.06–0.22)	0.99 (0.96–1.00)	0.90 (0.55–1.00)	0.66 (0.59–0.73)	15.84 (2.05– 122.6)	0.89 (0.81–0.97)
Xpert MTB/RIF Ultra (including trace)a	0.89 (0.79–0.96)	0.97 (0.93–0.99)	0.94 (0.84–0.98)	0.95 (0.90–0.98)	29.89 (11.3–78.8)	0.11 (0.06–0.22)
Xpert MTB/RIF Ultra (including trace)	0.83 (0.72–0.90)	0.99 (0.96–1.00)	0.98 (0.91–1.00)	0.91 (0.85–0.95)	109.12 (15.44–771.03)	0.17 (0.11–0.29)
CRP ≥10 mg/L visit 1	0.95 (0.87–0.98)	0.26 (0.19–0.34)	0.42 (0.34–0.49)	0.89 (0.75–0.97)	1.28 (1.14–1.43)	0.21 (0.08–0.57)
Symptoms not improved after antibiotics	0.43 (0.32–0.55)	0.86 (0.78–0.91)	0.63 (0.48– 0.76)	0.73 (0.65– 0.80)	3.00 (1.84– 4.91)	0.66 (0.54– 0.82)
CRP ≥10 mg/L after antibiotics	0.94 (0.86–0.98)	0.37 (0.28–0.46)	0.45 (0.37–0.53)	0.92 (0.81–0.98)	1.49 (1.29–1.72)	0.15 (0.06–0.40)

Reference standard of 2 sputum cultures unless stated.

Abbreviations: CI, confidence interval; CRP, C-reactive protein.

^aReference standard culture at visit 1 only (8 participants excluded due to contaminated cultures).