Table 3.

Comparison of CA and in-house PCR to the adapted gold standard

SpecimensAmplification systemNo. of adapted gold standard-positive specimensa that were PCR:No. of adapted gold standard-negative specimensb that were PCR:Sensitivity (%)Specificity (%)NPV (%)PPV (%)
PositiveNegativePositiveNegative
All (n= 1,527)CA673441,42266.3399.7197.6694.36
In house92921,42491.0899.8599.3797.87
Smear positiveCA2840087.5099.37
 (n = 32)cIn house3110096.8799.37
Smear negativeCA393041,42256.5299.7197.9390.69
 (n = 1,495)dIn house61821,42488.4099.8599.4496.82
  • a Specimens from patients with TB (for a definition, see Materials and Methods).

  • b Specimens from patients without any evidence of TB.

  • c Includes only specimens from TB patients.

  • d Includes six unspecific positive smears and 10 smear-positive specimens from patients infected with MOTT.