Table 1 Selected model parameters for post-calibration sensitivity analysis
Parameters | Base value | Low bound† | High bound | Reference |
|---|---|---|---|---|
Xpert diagnostic accuracy | ||||
Sensitivity—smear positive | 0.98 | 0.93 | 1.00 | [3] |
Sensitivity—smear negative | 0.67 | 0.60 | 0.85 | |
Sensitivity—RIF resistance | 0.95 | 0.90 | 0.97 | |
Specificity—diagnosis of TB disease | 0.99 | 0.98 | 1.00 | |
Specificity—RIF resistance | 0.98 | 0.97 | 1.00 | |
Treatment and linkage to care | ||||
Probability of empiric treatment at initial encounter | 0.25 | 0.00 | 0.50 | Assumption |
Probability of loss to follow-up after initial encounter | 0.13 | 0.05 | 0.25 | [10] |
Monthly rate of returning for follow-up encounter | 0.46 | 0.30 | 0.70 | [20] |
Probability of treatment failure for drug-resistant TB | 0.17 | 0.10 | 0.25 | WHO 2016 |
Probability of referring from private provider to public sector | 0.67 | 0.54 | 0.80 | [21] |
Type of costs | ||||
Cost of initial encounter | $12.11 | $9.08 | $15.14 | |
Cost of follow-up encounter | $9.53 | $7.15 | $11.91 | |
Cost of encounter to assess failing treatment | $7.39 | $5.54 | $9.24 | |
Other visits (informal/private) | $2.32 | $2.06 | $2.60 | |
DS-TB treatment, per 6-month course | $345.65 | $259.24 | $432.06 | |
DR-TB treatment, per course | $3399.22 | $2549.41 | $4249.02 | |