Treatment outcomes and survival based on drug resistance patterns in multidrug-resistant tuberculosis

Am J Respir Crit Care Med. 2010 Jul 1;182(1):113-9. doi: 10.1164/rccm.200911-1656OC. Epub 2010 Mar 11.


Rationale: Few large-scale studies have investigated multidrug-resistant tuberculosis (MDR-TB) treatment outcomes relative to drug-resistance patterns.

Objectives: To assess the impact of additional drug resistances on treatment outcomes and long-term survival in a large HIV-negative MDR-TB cohort.

Methods: Treatment outcomes and long-term survival of patients with MDR-TB newly diagnosed or retreated in 2000 to 2002 were retrospectively analyzed based on drug-resistance patterns after 5-8 years of follow-up.

Measurements and main results: Of 1,407 patients with MDR-TB, 75 (5.3%) had extensively drug-resistant TB (XDR-TB(re)) by the revised definition; 159 (11.3%) had ofloxacin-resistant pre-XDR-TB (pre-XDR-TB(o)); and 117 (8.3%) had second-line injectable drug (SLID)-resistant pre-XDR-TB (pre-XDR-TB(s)). Patients with XDR-TB(re) showed the lowest treatment success rate (29.3%) and the poorest long-term survival, and XDR-TB(re) was more strongly associated with long-term mortality than XDR-TB as originally defined (hazards ratio [HR], 3.15; 95% confidence interval [CI], 2.06-4.83; P < 0.001 vs. HR, 2.15; 95% CI, 1.49-3.09; P < 0.001). Patients with either form of pre-XDR-TB showed poorer cumulative survival than those with ofloxacin-susceptible/SLID-susceptible MDR-TB (P < 0.05 for each comparison). Although streptomycin susceptibility did not affect the treatment outcomes of patients with pre-XDR-TB, streptomycin-resistant pre-XDR-TB was more strongly associated with long-term mortality than ofloxacin-susceptible/SLID-susceptible MDR-TB (HR, 2.17; 95% CI, 1.22-3.84; P < 0.008 for pre-XDR-TB(o); and HR, 2.69; 95% CI, 1.40-5.16; P = 0.003 for pre-XDR-TB(s)).

Conclusions: The revised XDR-TB definition is appropriate for defining patients with MDR-TB with the poorest outcomes. Both pre-XDR-TB(o) and pre-XDR-TB(s) were independently associated with poor long-term survival in patients with MDR-TB. SM susceptibility was linked to better survival in patients with pre-XDR-TB.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Antitubercular Agents / therapeutic use*
  • Extensively Drug-Resistant Tuberculosis / classification
  • Extensively Drug-Resistant Tuberculosis / drug therapy*
  • Extensively Drug-Resistant Tuberculosis / mortality
  • Female
  • Fluoroquinolones / therapeutic use
  • Follow-Up Studies
  • Humans
  • Kaplan-Meier Estimate
  • Korea / epidemiology
  • Male
  • Medication Adherence
  • Microbial Sensitivity Tests
  • Middle Aged
  • Retrospective Studies
  • Streptomycin
  • Tuberculosis, Pulmonary / drug therapy*
  • Tuberculosis, Pulmonary / mortality
  • Young Adult


  • Antitubercular Agents
  • Fluoroquinolones
  • Streptomycin