Table 1 Pre and post intervention values for specific model parameters
From: Modeling the impact of tuberculosis interventions on epidemiologic outcomes and health system costs
Intervention (all public sector unless otherwise specified) | Model parameters influenced | Pre-intervention value | Notes and reference for pre intervention | Post-intervention value | Notes and Reference for post intervention |
|---|---|---|---|---|---|
Community Education | Patient delay (probability of seeking care with a 1 year delay) | 41 · 79 days = 0 · 11 probability of a 1 year delay | 21 days = 0 · 06 probability of a 1 year delay | Assume 50% reduction in delay days | |
DOTS expansion for diagnosis | Incorrect diagnostic test ordered by heath professional | 0 · 603 | [18] | 0 · 351 | [19] |
Diagnostic delay (probability of incurring a 1 year delay) | 29 · 49 days = 0 · 081 probability of a 1 year delay | 1 · 83 days = 0 · 005 probability of a 1 year delay | Used pre-intervention data and ratio of delay days "pre" and "post" intervention from [20] to obtain post-intervention estimate of delay days | ||
Loss to follow up during diagnostic work-up | 0 · 254 | [21-24] (Assume that loss to follow up is the same for regardless of provider) | 0 · 140 | Used pre-intervention data and ratio of outcomes "pre" and "post" intervention from [19] to obtain post-intervention estimated of loss to follow up | |
DOTS Expansion for Treatment | Incorrect treatment | 0 · 791 | [25] | 0 · 129 | [25] Scenario assumed that incorrect treatment was given regardless of DST availability |
Non specific DOTS Expansion (NTP Strengthening) | Initial access- inaccessible provider (ie · probability that patient seeks care with alternative provider that is inaccessible to interventions) | 0 · 055 | 0 · 025 | Intervention assumed to have same impact as in private sector | |
Private Sector interventions | Incorrect diagnostic test ordered by private provider | 0 · 622 | [18] | 0 · 362 | [19] |
Diagnostic delay (private sector only) | 0 · 11 | 0 · 007 | Used pre-intervention data and ratio of delay days "pre" and "post" intervention from [20] to obtain post-intervention estimate of delay days and then used ratio of outcomes in public vs private sector from [14] [27,32,33] to extrapolate estimate for public system to private system | ||
Loss to follow up during diagnosis (private sector only) | 0 · 254 | 0 · 140 | Assumed to be same as in public sector (a 45% reduction). Used pre-intervention data and ratio of outcomes "pre" and "post" intervention from [19] to obtain post-intervention estimated of drop out | ||
Incorrect treatment by private provider | 0 · 771 | [34] | 0 · 126 | Used pre-intervention data and ratio of outcomes "pre" and "post" intervention from [25] to obtain post-intervention estimate of incorrect treatment | |
HIV/ ART therapy programmes | TB Death rate in HIV/TB co-infected | 0 · 12 | [35] | 0 · 10 | [35] [36,37] (see table S5 in Supplement appendix for more detail) |
TB Relapse rate HIV/TB co-infected | 0 · 16 | [36] | 0 · 01 | [35] [36,37] (see table S5 in Supplement appendix for more detail) | |
TB Reactivation rate HIV/TB co-infected | 0 · 0340 | 0 · 02 | [41] | ||
MDR-TB related interventions | DST performed | 0 · 2 | Assumption | 0 · 5 | Assumption |
MDR- loss to follow up rate in HIV negative cases | 0 · 22 | [36] | 0 · 11 | Assumption- reduce rate to 50% |