TABLE 2.

NAAT performance statistics for Chlamydia trachomatis

Test% (no. of positive samples confirmed/total no. of positive samples) (CIa)
SensitivitySpecificityPPVNPV
First 500Total 1,000First 500Total 1,000First 500Total 1,000First 500Total 1,000
ProbeTec SDA82.6 (38/46) (68.6-92.2*)81.5 (75/92) (72.1-88.9*)100 (454/454) (99.2-100**)100 (908/908) (99.6-100**)100 (38/38) (90.7-100**)100 (75/75) (95.2-100**)98.3 (454/462) (96.6-99.2*)98.2 (908/925) (97.1-98.9*)
Aptima Combo2100 (46/46) (92.3-100**)100 (92/92) (96.1-100**)100 (454/454) (99.2-100**)100 (908/908) (99.6-100**)100 (46/46) (92.3-100**)100 (92/92) (96.1-100**)100 (46/46) (92.2-100**)100 (908/908) (99.6-100**)
Roche Amplicor PCR100 (46/46) (92.3-100**)NAb99.3 (451/454) (98.1-99.9*)NA93.9 (46/49) (83.1-98.7*)NA100 (451/451) (99.2-100**)NA
  • a *, 95% confidence interval (CI); **, 97.5% CI.

  • b NA, not applicable.