title: Prophylaxis for latent tuberculosis infection prior to anti–tumor necrosis factor therapy in low-risk elderly patients with rheumatoid arthritis: a decision analysis.
abstract: OBJECTIVE
  To determine if low-risk elderly patients with rheumatoid arthritis (RA) who screen positive for latent tuberculosis (TB) infection prior to anti–tumor necrosis factor (anti-TNF) therapy should be given isoniazid (INH).
  
  
  METHODS
  A Markov model was developed. The base case was a patient age 65 years with RA starting anti-TNF therapy with a positive tuberculin skin test (TST) finding of 5–9 mm, who was born in a country with low TB prevalence and had no other TB risk factors. The decision was 9 months of INH or not. The primary outcome was quality-adjusted life expectancy. Multiple sensitivity analyses were performed.
  
  
  RESULTS
  No prophylaxis was favored, with a gain of 1.1 quality-adjusted life days, but the decision was sensitive to several variables. Prophylaxis was favored for patients ages <61 years, if the relative risk (RR) of TB reactivation with RA alone was >2.5, if the RR with anti-TNF therapy was >5.8, or if the utility associated with INH therapy was >0.98. Prophylaxis was also preferred for patients with a TST result >10 mm and for patients from higher risk countries. If 6 months of INH or 4 months of rifampin were used, prophylaxis was preferred, providing that therapy reduced the risk of TB reactivation by >47% and >27%, respectively.
  
  
  CONCLUSIONS
  Withholding prophylaxis prior to anti-TNF therapy may be reasonable for low-risk elderly RA patients with a TST finding of 5–9 mm, although the decision is sensitive to patient preferences. For patients age <61 years from a higher risk country, or with a TST finding >10 mm, prophylaxis is preferred.
authors.forename: Glen S
authors.initials: GS
authors.lastname: Hazlewood
authors.forename: David
authors.initials: D
authors.lastname: Naimark
authors.forename: Michael
authors.initials: M
authors.lastname: Gardam
authors.forename: Vivian
authors.initials: V
authors.lastname: Bykerk
authors.forename: Claire
authors.initials: C
authors.lastname: Bombardier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000995:Antitubercular Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000188:drug therapy; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D007538:Isoniazid / Q000627:therapeutic use*; D055985:Latent Tuberculosis / Q000150:complications / Q000188:drug therapy / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; D014409:Tumor Necrosis Factor-alpha; D007538:Isoniazid