Parameter | Value | Source |
---|---|---|
Epidemiological Parameters | ||
Age at screening | 30 | Assumption |
Prevalence of active TB in refugee camps (Per 100,000) | ||
High Prevalence | 955 | [28] |
Moderate Prevalence | 426 | [28] |
Low Prevalence | 9 | [28] |
TST sensitivity | 89 % | [32] |
TST specificity | ||
Non BCG vaccinated populations | 98 % | [34] |
BCG vaccinated during infancy only | 92 % | [34] |
BCG vaccinated after infancy | 60 % | [34] |
Overall TST specificitya | 85 % | calculated |
Proportion with positive TST | ||
High Prevalence | 55 % | |
Moderate Prevalence | 35 % | |
Low Prevalence | 20 % | |
True prevalence of LTBIb | ||
High Prevalence | 54 % | calculated |
Moderate Prevalence | 27 % | calculated |
Low Prevalence | 7 % | calculated |
Probability of abnormal chest radiograph with active disease | 100 % | [33] |
Probability of abnormal chest radiograph with LTBI (inactive TB) | 11 % | [33] |
Specificity of chest radiograph with no infection | 95 % | [35] |
Probability of accepting 12-dose weekly isoniazid-rifapentine regimen overseas with positive TST | 95 % | [14] |
Probability of completing 12-dose weekly isoniazid-rifapentine regimen overseas | 95 % | |
Probability of active TB during first year of resettlement for Class B1 refugeesc | 1.5 % | [36] |
Probability of presenting for domestic follow-up at U.S. health department | 76 % | [7] |
Probability of receiving TST at domestic follow-up (Class B1) | 75 % | [assumption] |
Probability of receiving TST at domestic follow-up (No TB class) | 50 % | [assumption] |
Probability of accepting latent treatment in U.S. with positive TST | 77 % | [38] |
Probability of completing 12-dose weekly isoniazid-rifapentine regimen in U.S. | 82 % | [11] |
Effectiveness of completed 12-dose weekly isoniazid-rifapentine regimen in preventing active TB | 93 % | [39] |
Effectiveness of partially completed 12-dose weekly isoniazid-rifapentine regimen in preventing active TB | 0 % | [39] |
Annual risk of progression to active TB with untreated latent disease | 0.1 % | [30] |
Background Mortality | Varies with age | [23] |
Cost Parametersd | ||
Costs of TST used in overseas screening with hypothetical protocol | ||
Base Case (average across originating countries) | $4.50 | Kenyan panel physicians and [42] |
Lowest TST Cost | $3.50 | Kenyan panel physicians and [42] |
Highest TST Cost | $5.15 | Kenyan panel physicians and [42] |
Cost of TST in U.S. | $24.00 | [43] |
Costs of 12 weekly 900 mg rifapentine doses through U.S. government | $72.00 | [51] |
Costs of 12 weekly 900 mg isoniazid doses through Global Drug Facility | $0.72 | [49] |
Costs of labor to administer DOT during latent treatment | ||
Average labor cost in refugee camp | $13.40 | |
U.S. | $38.70 | |
Costs of active TB case in U.S. | $18,100 |