title: Treatment outcomes and long-term survival in patients with extensively drug-resistant tuberculosis.
abstract: BACKGROUND
  The increasing worldwide incidence of extensively drug-resistant tuberculosis (XDR-TB) has emerged as a threat to public health and tuberculosis (TB) control. Treatment outcomes have varied among studies, and data on long-term survival are still scarce.
  
  
  OBJECTIVE
  To retrospectively assess the burden, clinical characteristics, treatment outcomes, and long-term survival rate of patients with XDR-TB in a cohort of patients with HIV-negative multidrug-resistant tuberculosis (MDR-TB) in South Korea.
  
  
  METHODS
  Medical records were reviewed of patients newly diagnosed with or retreated for MDR-TB from 2000 to 2002. The cohort was monitored for 3 to 7 years after the initiation of treatment. Initial treatment outcomes and cumulative survival rates were analyzed, and predictors of treatment success and survival were defined.
  
  
  RESULTS
  Of 1,407 patients with MDR-TB 75 (5.3%) had XDR-TB at treatment initiation. The default rate was high (453/1,407; 32%), and patients with XDR-TB had lower treatment success (29.3 vs. 46.2%; P = 0.004) and higher all-cause (49.3 vs. 19.4%; P < 0.001) and TB-related disease mortality (41.3 vs. 11.8%; P < 0.001) than other patients with MDR-TB. The presence of XDR-TB significantly affected treatment success (odds ratio, 0.23; 95% confidence interval [CI], 0.08-0.64; P = 0.005), all-cause mortality (hazards ratio, 3.25; 95% CI, 1.91-5.53; P < 0.001), and TB-related mortality (hazards ratio, 4.45; 95% CI, 2.48-8.00; P < 0.001) on multivariate analyses.
  
  
  CONCLUSIONS
  XDR-TB occurred in a substantial proportion of patients with MDR-TB in South Korea, and was the strongest predictor of treatment outcomes and long-term survival in patients with MDR-TB. Adequate TB control policies should be implemented to prevent the further development and spread of drug resistance.
authors.affiliation: Department of Internal Medicine, Dankook University College of Medicine, Dankook University Hospital, Cheonan, South Korea.
authors.forename: Doh Hyung
authors.initials: DH
authors.lastname: Kim
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Seung-Kyu
authors.initials: SK
authors.lastname: Park
authors.forename: Suck-Jun
authors.initials: SJ
authors.lastname: Kong
authors.forename: Young Sam
authors.initials: YS
authors.lastname: Kim
authors.forename: Tae-Hyung
authors.initials: TH
authors.lastname: Kim
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Ki Man
authors.initials: KM
authors.lastname: Lee
authors.forename: Sung Soon
authors.initials: SS
authors.lastname: Lee
authors.forename: Jae Seuk
authors.initials: JS
authors.lastname: Park
authors.forename: Won-Jung
authors.initials: WJ
authors.lastname: Koh
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Lee
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Kim
authors.forename: Tae Sun
authors.initials: TS
authors.lastname: Shim
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D054908:Extensively Drug-Resistant Tuberculosis / Q000188:drug therapy* / Q000601:surgery; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007723:Korea; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D055502:Secondary Prevention
chemical_list: D000900:Anti-Bacterial Agents