Table 4.

INH assay results of Hain and RT MTB RIF/INH compared against DST

Assay results	DST
Hain	Resistant	Sensitive
INH resistant	26	0
INH sensitive	6	90
Hain INH sensitivity −81.3% (26/32) [95% CI 63.6%–92.8%]
Hain INH specificity −100% (90/90) [95% CI 96.0%–100.0%]
Hain INH PPV −100.0% (26/26) [95% CI 86.8%–100.0%]
Hain INH NPV −93.8% (90/96) [95% CI 86.9%–97.7%]
RT MTB RIF/INH	Resistant	Sensitive
INH resistant	28	5
INH sensitive	4	85
RT MTB RIF/INH INH sensitivity −87.5% (28/32) [95% CI 71.0%–96.5%]
RT MTB RIF/INH INH specificity −94.4% (85/90) [95% CI 87.5%–98.2%]
RT MTB RIF/INH INH PPV −84.8% (28/33) [95% CI 68.1%–94.9%]
RT MTB RIF/INH INH NPV −95.5% (85/89) [95% CI 88.9%–98.8%]

Abbreviations: RT MTB RIF/INH, RealTime MTB RIF/INH Resistance Assay; MTB, Mycobacterium tuberculosis; RIF, rifampicin; INH, isoniazid; DST, drug sensitivity testing; PPV, positive predictive value; NPV, negative predictive value.