Table 1– Sensitivities, specificities, and positive and negative predictive values for each of the four different smear detection methods stratified by HIV status and CD4 cell count
Study groupSputum samples nSensitivitySpecificity
Unconcentrated sputum sampleConcentrated sputum pelletUnconcentrated sputum sampleConcentrated sputum pellet
ZNLEDMVFMLEDZNLEDMVFMLED
All61649#,¶ (42–57)52#,+ (44–59)66 (58–73)66¶,+ (58–73)99 (98–100)100 (98–100)99 (98–100)99 (98–100)
HIV-negative37755§ (45–65)57ƒ (46–66)74## (64–82)71¶¶ (61–79)99 (97–100)99 (97–100)99 (97–100)99 (97–100)
HIV-positive15039§,++,§§ (26–54)46ƒ,++ (32–61)46##,ƒƒ (32–61)54¶¶,§§,ƒƒ (39–68)100 (97–100)100 (97–100)100 (97–100)99 (95–100)
CD4 count <200 cells·mL−16939 (20–61)50 (29–71)44### (25–66)56### (34–75)100 (93–100)100 (93–100)100 (93–100)100 (93–100)
  • Culture positivity to Mycobacterium tuberculosis served as the reference standard. Data are presented as median (95% CI), unless otherwise stated. ZN: Ziehl–Neelsen staining light microscopy; LED: auramine O staining light-emitting diode fluorescent microscopy; MVFM: auramine O staining conventional mercury vapour fluorescent microscopy. #: p=0.33; : p=0.001; +: p=0.005; §: p=0.08; ƒ: p=0.28; ##: p=0.002; ¶¶: p=0.06; ++: p=0.25; §§: p=0.092; ƒƒ: p=0.5; ###: p=0.5.