title: USPHS Tuberculosis Short-Course Chemotherapy Trial 21: effectiveness, toxicity, and acceptability. The report of final results.
abstract: OBJECTIVE
  To determine the effectiveness, toxicity, and acceptability of a 6-month antituberculous regimen compared with a 9-month regimen.
  
  
  METHODS
  A nonblinded, unbalanced, randomized, multicenter clinical trial.
  
  
  METHODS
  Twenty-two tuberculosis clinics in public health departments and hospitals in the United States.
  
  
  METHODS
  Patients were eligible if Mycobacterium tuberculosis, isolated from sputum cultures, was susceptible to study drugs. Of 1451 patients enrolled, 75% (617 of 823) assigned to the 6-month regimen and 71% (445 of 628) assigned to the 9-month regimen were eligible.
  
  
  METHODS
  Patients took self-administered isoniazid and rifampin daily for 24 weeks (6-month regimen) or 36 weeks (9-month regimen). In addition, patients assigned to the 6-month regimen took self-administered pyrazinamide daily during the first 8 weeks.
  
  
  RESULTS
  Patients on the 6-month regimen converted more rapidly than patients on the 9-month regimen (94.6% compared with 89.9% after 16 weeks of therapy, with a difference of 4.7% [95% CI, 0.7% to 8.7%]); had similar rates of adverse drug reactions (7.7% compared with 6.4%, with a difference of 1.3% [95% CI, 0.0% to 4.6%]); had lower noncompliance rates (16.8% compared with 29.2%, with a difference of 12.4% [95% CI, 6.8% to 18.0%]); and had similar relapse rates 96 weeks after completing therapy (3.5% compared with 2.8%, with a difference of 0.7% [95% CI, 0.0% to 3.9%]). A significantly greater proportion of patients assigned to the 6-month regimen successfully completed therapy (61.4% compared with 50.6%; chi 2 = 11.976).
  
  
  CONCLUSIONS
  Our results suggest that this 6-month regimen is similar in effectiveness, toxicity, and acceptability to the 9-month regimen for treating pulmonary tuberculosis.
authors.affiliation: Centers for Disease Control, Atlanta, Georgia.
authors.forename: D L
authors.initials: DL
authors.lastname: Combs
authors.forename: R J
authors.initials: RJ
authors.lastname: O'Brien
authors.forename: L J
authors.initials: LJ
authors.lastname: Geiter
mesh_terms: D000328:Adult; D000995:Antitubercular Agents / Q000008:administration & dosage* / Q000009:adverse effects; D002487:Centers for Disease Control and Prevention, U.S.; D003627:Data Interpretation, Statistical; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D004977:Ethambutol / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007538:Isoniazid / Q000008:administration & dosage; D008297:Male; D015337:Multicenter Studies as Topic; D010349:Patient Compliance; D016016:Proportional Hazards Models; D011718:Pyrazinamide / Q000008:administration & dosage; D016032:Randomized Controlled Trials as Topic; D012008:Recurrence; D012293:Rifampin / Q000008:administration & dosage; D013183:Sputum / Q000382:microbiology; D015996:Survival Rate; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy*; D014481:United States
chemical_list: D000995:Antitubercular Agents; D011718:Pyrazinamide; D004977:Ethambutol; D007538:Isoniazid; D012293:Rifampin