India is replacing culture and drug sensitivity testing (CDST) with rapid molecular tests for diagnosing MDR-TB. We assessed the impact of rapid tests on time to initiation of treatment and outcomes in patients with MDR-TB compared with CDST.Methods
A retrospective cohort study involving MDR-TB patients from six districts in Tamil Nadu state, who underwent CDST (2010–2011) and rapid tests (2012–2013).Results
There were 135 patients in the CDST group and 389 in the rapid diagnostic test group. Median time from sputum receipt at the laboratory to initiation of MDR-TB treatment was 130 days (IQR 75–213) in the CDST group and 22 days (IQR 14–38) in the rapid diagnostic test group (p<0.001). Overall treatment success was 30% with CDST and 41% with rapid tests (p<0.05), but there was high loss to follow-up >30% in both groups and missing data were higher in CDST (13%) compared with rapid tests (3%). There were significantly higher risks of unfavourable treatment outcomes in males (aRR 1.3, 95% CI 1.1–1.5) and those with treatment initiation delays >30 days (aRR 1.3, 95% CI 1.0–1.6).Conclusion
Rapid molecular diagnostic tests shortened the time to initiate treatment which was associated with reduced unfavourable outcomes in MDR-TB patients. This supports the policy to scale up these tests in India.