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Table 1 Decision analysis model parameters related to the natural history, epidemiology, and treatment of LTBI and TB

From: The potential impact and cost-effectiveness of tobacco reduction strategies for tuberculosis prevention in Canadian Inuit communities

Estimates Reference
Probabilities Probability (%)*  
 •Probability of diagnosing LTBI 25 Assumption
 •Probability of completing LTBI treatment among those who start it 70.8 [69]
 •Probability of reactivation of longstanding LTBI to TB disease (non-smokers) 0.05/year [70,71,72]
 •Probability of rapid progression following TB infection (non-smokers)** 4.5/year for 2 years Dynamic model#
 •Probability of diagnosing active disease 90 Assumption
 •Probability of spontaneous resolution of untreated TB disease 25 [16]
 •Probability of relapse following spontaneously resolved TB 2.5 [16, 73]
 •Probability of dying from untreated TB 19/year [74, 75]
 •Probability of relapse after treated TB disease in first year 1.5 [76]
 •Protective immunity from previous TB disease 55 Dynamic model#
QALYs for LTBI and active TB Value (range)  
 •Utility score for individual with active disease (treated) 0.85 (0.70–0.90) [40]
 •Utility score for individual with active disease (untreated) 0.68 (0.65–0.72) [39]
 •Utility score for individual with latent infection, during treatment 0.97 (0.95–1.00) [40]
 •Utility score for individual with latent infection (untreated) 1 Assumption
  1. INH isoniazid, LTBI latent tuberculosis infection, QALYs quality-adjusted life-years
  2. *Probabilities are one-time percentages, unless stated otherwise
  3. **After 2 years, risk of developing active TB falls to 0.05% annually
  4. Persons with LTBI are asymptomatic
  5. #Calibrated in dynamic model