title: Risk factors for treatment default in close contacts with latent tuberculous infection.
abstract: OBJECTIVE
  1) To characterize risk factors for non-completion of latent tuberculous infection treatment (LTBIT), and 2) to assess the impact of LTBIT regimens on subsequent risk of tuberculosis (TB).
  
  
  METHODS
  Close contacts of adults aged ⩾15 years with pulmonary TB were prospectively enrolled in a multi-center study in the United States and Canada from January 2002 to December 2006. Close contacts of TB patients were screened and cross-matched with TB registries to identify those who developed active TB.
  
  
  RESULTS
  Of 3238 contacts screened, 1714 (53%) were diagnosed with LTBI. Preventive treatment was recommended in 1371 (80%); 1147 (84%) initiated treatment, of whom 723 (63%) completed it. In multivariate analysis, study site, initial interview sites other than a home or health care setting and isoniazid preventive treatment (IPT) were significantly associated with non-completion of LTBIT. Fourteen TB cases were identified in contacts, all of whom initiated IPT: two TB cases among persons who received ⩾6 months of IPT (66 cases/100 000 person-years [py]), and nine among those who received 0-5 months (median 2 months) of IPT (792 cases/100 000 py, P < 0.001); data on duration of IPT were not available for three cases.
  
  
  CONCLUSIONS
  Only 53% (723/1371) of close contacts for whom IPT was recommended actually completed treatment. Close contacts were significantly less likely to complete LTBIT if they took IPT. Less than 6 months of IPT was associated with increased risk of active TB.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: C T
authors.initials: CT
authors.lastname: Fiske
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: F-X
authors.initials: FX
authors.lastname: Yan
authors.affiliation: Charles P Felton National Tuberculosis Center, International Center for AIDS Care and Treatment Programs, Mailman School of Public Health, Columbia University, New York, New York, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Hirsch-Moverman
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: T R
authors.initials: TR
authors.lastname: Sterling
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Reichler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000995:Antitubercular Agents / Q000627:therapeutic use*; D002170:Canada; D016009:Chi-Square Distribution; D016358:Contact Tracing; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007538:Isoniazid / Q000627:therapeutic use; D055985:Latent Tuberculosis / Q000175:diagnosis / Q000188:drug therapy* / Q000635:transmission; D016015:Logistic Models; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; D007538:Isoniazid