title: Impact of rapid molecular diagnostic tests on time to treatment initiation and outcomes in patients with multidrug-resistant tuberculosis, Tamil Nadu, India.
abstract: 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.
  
  
  
  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).
  
  
  
  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).
  
  
  
  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.
authors.affiliation: National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India dinanair73@yahoo.co.in.
authors.forename: Dina
authors.initials: D
authors.lastname: Nair
authors.affiliation: National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India.
authors.forename: Pooranaganga D
authors.initials: PD
authors.lastname: Navneethapandian
authors.affiliation: International Union Against Tuberculosis and Lung Disease, South-East Asia Regional Office, New Delhi, India.
authors.forename: Jaya Prasad
authors.initials: JP
authors.lastname: Tripathy
authors.affiliation: International Union Against Tuberculosis and Lung Disease, Paris, France.|London School of Hygiene and Tropical Medicine, Keppel Street, London, UK.
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Harries
authors.affiliation: National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India.
authors.forename: Joel S
authors.initials: JS
authors.lastname: Klinton
authors.affiliation: National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India.
authors.forename: Basilea
authors.initials: B
authors.lastname: Watson
authors.affiliation: National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India.
authors.forename: Gomathi N
authors.initials: GN
authors.lastname: Sivaramakrishnan
authors.affiliation: National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India.
authors.forename: Devarajulu S
authors.initials: DS
authors.lastname: Reddy
authors.affiliation: State TB Cell, Directorate of Health Services, Tamil Nadu, India.
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Murali
authors.affiliation: National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India.
authors.forename: Mohan
authors.initials: M
authors.lastname: Natrajan
authors.affiliation: Indian Council of Medical Research, New Delhi, India.
authors.forename: Soumya
authors.initials: S
authors.lastname: Swaminathan
mesh_terms: D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D011050:Policy Making; D011634:Public Health / Q000379:methods; D012189:Retrospective Studies; D013183:Sputum / Q000382:microbiology; D061665:Time-to-Treatment / Q000458:organization & administration / Q000706:statistics & numerical data*; D016896:Treatment Outcome; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents
keywords: India, Line probe assay; Multidrug-resistant tuberculosis; Rapid molecular tests; Treatment outcomes; Xpert MTB/RIF