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Table 4 Sensitivity and specificity of the LAM test, sputum smear microscopy and combinations of the tests

From: Diagnostic accuracy of the rapid urine lipoarabinomannan test for pulmonary tuberculosis among HIV-infected adults in Ghana–findings from the DETECT HIV-TB study

  Total Sensitivity Specificity LR (+) LR (−) PPV NPV
N % (95 % CI) N % (95 % CI) % (95 % CI) % (95 % CI) % (95 % CI) % (95 % CI)
LAM test 469 24/55 44 (30–58) 393/414 95 (92–97) 8.6 (5.1-14.4) 0.6 (0.5-0.8) 53 (38–68) 93 (90–95)
ZN microscopy 467 29/55 53 (39–66) 406/412a 99 (97–100) 36.2 (15.7-83.3) 0.5 (0.4-0.6) 83 (66–93) 94 (91–96)
ZN + Fluorescence microscopy 467 31/55 56 (42–70) 406/412a 99 (97–100) 38.7 (16.9-88.5) 0.4 (0.3-0.6) 84 (68–94) 94 (92–96)
LAM + ZN microscopy 469 34/55 62 (48–75)a 388/414 94 (90–96)a,b 9.8 (6.4-15.1) 0.4 (0.3-06) 57 (43–69) 95 (92–97)
LAM + ZN + Fluorescence Microscopy 469 35/55 64 (50–76)a 388/414 94 (91–96)a,c 10.1 (6.6-15.5) 0.4 (0.3-0.6) 57 (44–70) 95 (93–97)
  1. For combinations of test a positive result was recorded if any of the tests were positive
  2. ap < 0.05 for comparison with LAM test alone
  3. bp < 0.05 for comparison with ZN microscopy alone
  4. cp < 0.05 for comparison with ZN + Fluorescence microscopy
  5. LR (+) = Positive Likelihood Ratio, LR (−) = Negative Likelihood Ratio, PPV = Positive Predictive Value, NPV = Negative Predictive Value, ZN = Ziehl Neelsen
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