title: The effect of the Xpert MTB/RIF test on the time to MDR-TB treatment initiation in a rural setting: a cohort study in South Africa's Eastern Cape Province.
abstract: There are significant delays in initiation of multidrug-resistant tuberculosis (MDR -TB) treatment. The Xpert MTB/RIF test has been shown to reduce the time to diagnosis and treatment of MDR-TB predominantly in urban centres. This study describes the time to treatment of MDR-TB and the effect of Xpert MTB/RIF on time to treatment in a deprived rural area in South Africa.
  
  
  
  This was a retrospective cohort study analysing the medical records of patients diagnosed with MDR-TB in King Sabata Dalindyebo Sub-District between 2009 and 2014. Numerical data were reported using the Kruskal-Wallis and Wilcoxon sum rank tests and categorical data compared using the two-sample test of proportions.
  
  
  
  Of the 342 patients with MDR-TB identified, 285 were eligible for analysis, of whom 145 (61.4%) were HIV positive. The median time from sputum collection to MDR-TB diagnosis was 27 days (IQR: 2-45) and differed significantly between diagnostic modalities: Xpert MTB/RIF, 1 day (IQR: 1-4; n = 114: p < 0.0001); Line Probe Assay 12 days (IQR: 8-21; n = 28; p < 0.0001); and culture/phenotypic drug sensitivity testing 45 days (IQR: 39-59; n = 143: p < 0.0001). The time from diagnosis to treatment initiation was 14 days (IQR: 8-27) and did not differ significantly between diagnostic modality. The median time from sputum collection to treatment initiation was 49 days (IQR: 20-69) but differed significantly between diagnostic modalities: Xpert MTB/RIF, 18 days (IQR: 11-27; n = 114; p < 0.0001); Line Probe Assay 29 days (IQR: 14.5-53; n = 28; p < 0.0001); and culture/phenotypic drug sensitivity, 64 days (IQR: 50-103; n = 143: P < 0.0001). Age, sex and HIV status did not influence the time intervals.
  
  
  
  Xpert MTB/RIF significantly reduced the time to MDR-TB treatment in a deprived rural setting as a result of a reduced time to diagnosis. However, the national target of five days was not achieved. Further research is needed to explore and address programmatic and patient-related challenges contributing to delayed treatment initiation.
authors.affiliation: Department of Family Medicine and Rural Health, Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa.
authors.forename: Joshua
authors.initials: J
authors.lastname: Iruedo
authors.affiliation: Department of Family Medicine and Rural Health, Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa. donomahony@gmail.com.
authors.forename: Don
authors.initials: D
authors.lastname: O'Mahony
authors.affiliation: Department of Public Health, Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa.
authors.forename: Sikhumbuzo
authors.initials: S
authors.lastname: Mabunda
authors.affiliation: Centre for Health Informatics Research and Development, Faculty of Health Sciences, University of Fort Hare, Alice, South Africa.
authors.forename: Graham
authors.initials: G
authors.lastname: Wright
authors.affiliation: Department of Family Medicine and Rural Health, Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa.
authors.forename: Busisiwe
authors.initials: B
authors.lastname: Cawe
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D057210:Delayed Diagnosis / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques; D012189:Retrospective Studies; D012424:Rural Population; D012680:Sensitivity and Specificity; D013019:South Africa; D061665:Time-to-Treatment; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000188:drug therapy; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000188:drug therapy; D055815:Young Adult
keywords: Cohort study; MDR-TB; Rural; Time-to-treatment; Xpert MTB/RIF