Background
Methods
General approach to modeling
Population
Overview of decision analysis model
Pre-intervention inputs
Epidemiologic inputs
Diagnostic and treatment related inputs
Health system costs
Interventions
Key model parameters affected by intervention
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 | 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 | |||
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 | |
TB Relapse rate HIV/TB co-infected | 0 · 16 | [36] | 0 · 01 | ||
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% |
Projected outcomes
Sensitivity analysis
Ethics statement
Availability of supporting data
Results
Impact of interventions to improve diagnosis and treatment of TB in the public and/or private sectors in a low MDR/low HIV setting. Indonesia case study.
Intervention | Specific parameter changed1 | Primary active cases arising in cohort over 20 years3 | Total projected outcomes related to the primary cases | |||||
---|---|---|---|---|---|---|---|---|
Parameter | Pre-intervention | Post-intervention | Death during diagnosis/treatment phase | Cure due to treatment | Secondary cases generated from primary cases | Health system costs | ||
Baseline | - | - | - | 19 · 27 | 12 · 52 | 0 · 97 | 28 · 87 | $2,641 · 47 |
Community Education | Patient delay2 | 11% | 6% | 19 · 27 | 12 · 39 | 0 · 99 | 28 · 54 | $2,696 · 70 |
DOTS expansion for diagnosis | Incorrect Diagnostic Test (in public sector) | 60% | 35% | 19 · 27 | 11 · 90 | 1 · 24 | 27 · 38 | $3,302 · 55 |
Diagnostic Delay2 (in public sector) | 8% | 0 · 5% | 19 · 27 | 12 · 48 | 0 · 98 | 28 · 71 | $2,670 · 63 | |
Loss to follow up during Diagnosis (in public sector) | 25% | 14% | 19 · 27 | 12 · 37 | 1 · 03 | 28 · 51 | $2,800 · 83 | |
DOTS Expansion for Treatment | Incorrect Treatment (in public sector) | 79% | 13% | 19 · 27 | 12 · 02 | 2 · 33 | 27 · 89 | $2,646 · 61 |
Non specific DOTS Expansion (NTP Strengthening) | Access Government Facility | 43% | 73% | 19 · 27 | 12 · 42 | 0 · 99 | 28 · 62 | $2,764 · 86 |
Private Sector interventions | Incorrect Diagnostic test (in private sector) | 62% | 36% | 19 · 27 | 11 · 75 | 1 · 33 | 27 · 04 | $3,455 · 53 |
Diagnostic Delay2 (in private sector) | 11% | 0 · 7% | 19 · 27 | 12 · 46 | 0 · 98 | 28 · 63 | $2,685 · 49 | |
Loss to follow up during Diagnosis (in private sector) | 25% | 14% | 19 · 27 | 12 · 35 | 1 · 05 | 28 · 46 | $2,823 · 16 | |
Incorrect Treatment (in private sector) | 77% | 13% | 19 · 27 | 11 · 97 | 2 · 48 | 27 · 79 | $2,647 · 19 | |
HIV/ ART therapy programmes | HIV (+) Death | 12% | 10% | 19 · 27 | 12 · 52 | 0 · 97 | 28 · 87 | $2,641 · 47 |
HIV (+) Relapse | 16% | 1% | 19 · 27 | 12 · 52 | 0 · 97 | 28 · 87 | $2,641 · 47 | |
HIV (+) Reactivation | 3 · 4% | 2% | 19 · 26 | 12 · 52 | 0 · 96 | 28 · 86 | $2,640 · 66 | |
MDR-TB related interventions | DST performed | 20% | 50% | 19 · 27 | 12 · 52 | 0 · 97 | 28 · 87 | $2,693 · 77 |
Loss to follow up during MDR Treatment | 22% | 11% | 19 · 27 | 12 · 52 | 0 · 97 | 28 · 87 | $2,642 · 53 |
Intervention | Specific parameter changed1 | Change in outcomes related to primary active cases and ranking of impact3 | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Parameter | Pre-intervention | Post-intervention | Death during diagnosis and treatment phase | Cure due to treatment | Secondary cases generated from primary cases | Health system costs | |||||
Change in outcome | Rank of impact | Change in outcome | Rank of impact | Change in outcome | Rank of impact | Change in outcome | Rank of impact | ||||
Baseline | - | - | - | 12 · 52 | - | 0 · 97 | - | 28 · 87 | - | $2,641 · 47 | - |
Community Education | Patient delay2 | 11% | 6% | −0 · 14 | 7 | 0 · 02 | 7 | −0 · 33 | 7 | 55 · 24 | 10 |
DOTS expansion for diagnosis | Incorrect Diagnostic Test (in public sector) | 60% | 35% | −0 · 62 | 2 | 0 · 27 | 4 | −1 · 49 | 2 | 661 · 09 | 14 |
Diagnostic Delay2 (in public sector) | 8% | 0 · 5% | −0 · 04 | 10 | 0 · 01 | 10 | −0 · 16 | 10 | 29 · 16 | 7 | |
Loss to follow up during Diagnosis (in public sector) | 25% | 14% | −0 · 15 | 6 | 0 · 07 | 6 | −0 · 36 | 6 | 159 · 37 | 12 | |
DOTS Expansion for Treatment | Incorrect Treatment (in public sector) | 79% | 13% | −0 · 50 | 4 | 1 · 36 | 2 | −0 · 98 | 4 | 5 · 15 | 5 |
Non specific NTP Strengthening | Access Government Facility | 43% | 73% | −0 · 10 | 8 | 0 · 02 | 7 | −0 · 25 | 8 | 123 · 40 | 11 |
Private Sector interventions | Incorrect Diagnostic test (in private sector) | 62% | 36% | −0 · 77 | 1 | 0 · 37 | 3 | −1 · 84 |
1
| 814 · 07 | 15 |
Diagnostic Delay2 (in private sector) | 11% | 0 · 7% | −0 · 07 | 9 | 0 · 02 | 7 | −0 · 24 | 9 | 44 · 02 | 8 | |
Loss to follow up during Diagnosis (private sector) | 25% | 14% | −0 · 17 | 5 | 0 · 08 | 5 | −0 · 41 | 5 | 181 · 69 | 13 | |
Incorrect Treatment (in private sector) | 77% | 13% | −0 · 56 | 3 | 1 · 51 | 1 | −1 · 08 | 3 | 5 · 72 | 6 | |
HIV/ ART therapy programmes | HIV/TB Death rate | 12% | 10% | 0 · 00 | 11 | 0 · 00 | 11 | 0 · 00 | 13 | 0 · 00 | 2 |
HIV/TB Relapse rate | 16% | 1% | 0 · 00 | 11 | 0 · 00 | 11 | 0 · 00 | 13 | 0 · 00 | 2 | |
HIV/TB Reactivation rate | 3 · 4% | 2% | 0 · 00 | 11 | 0 · 00 | 11 | −0 · 01 | 11 | −0 · 81 |
1
| |
MDR-TB related interventions | DST performed | 20% | 50% | 0 · 00 | 11 | 0 · 00 | 11 | −0 · 01 | 11 | 52 · 31 | 9 |
Loss to follow up during MDR Treatment | 22% | 11% | 0 · 00 | 11 | 0 · 00 | 11 | 0 · 00 | 13 | 1 · 07 | 4 |
Scenario | Primary active cases arising in cohort over 20 years1 | Total projected outcomes related to the primary active cases | ||||
---|---|---|---|---|---|---|
Death during diagnosis phase | Death during treatment phase | Cure due to treatment | Secondary cases generated from primary cases | Health system costs | ||
Baseline | 19 · 27 | 11 · 01 | 1 · 51 | 0 · 97 | 28 · 87 | $2,641 · 47 |
Eliminate patient delay in seeking care | 19 · 27 | 10 · 67 | 1 · 57 | 1 · 01 | 28 · 21 | $2,751 · 94 |
Above & Eliminate informal sector for TB diagnosis | 19 · 27 | 10 · 45 | 1 · 67 | 1 · 06 | 27 · 88 | $2,916 · 34 |
Above & Increase correct diagnostic test to 100% | 19 · 27 | 4 · 11 | 4 · 31 | 2 · 75 | 18 · 64 | $6,809 · 05 |
Above & Eliminate health system diagnostic delay | 19 · 27 | 3 · 67 | 4 · 44 | 2 · 84 | 17 · 40 | $7,013 · 83 |
Above & Increase correct treatment to 100% | 19 · 27 | 3 · 67 | 0 · 72 | 12 · 95 | 9 · 59 | $7,052 · 06 |
Above & Eliminate loss to follow up prior to starting treatment | 19 · 27 | 0 | 0 · 96 | 17 · 35 | 1 · 39 | $9,295 · 09 |
Impact of interventions to improve diagnosis and treatment of TB in a high MDR-TB or high HIV-TB setting. Kazakhstan and Mozambique case studies.
General intervention | Specific parameter changed1 | Projected changes in outcomes related to the primary active cases and Ranking of impact3 | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Parameter | Pre-intervention | Post-intervention | Death during diagnosis and treatment phase | Cure due to treatment | Secondary cases generated from primary cases | Health system costs | |||||
Change in outcome | Rank of impact | Change in outcome | Rank of impact | Change in outcome | Rank of impact | Change in outcome | Rank of impact | ||||
Baseline outcomes | - | - | - | 10 · 05 | 0 · 62 | 22 · 99 | $5,238 · 87 | ||||
Community Education | Patient delay2 | 11% | 6% | −0 · 14 | 3 | 0 · 01 | 5 | −0 · 26 | 5 | 111 · 34 | 3 |
DOTS expansion for diagnosis | Incorrect Diagnostic Test | 60% | 35% | −1 · 88 |
1
| 0 · 40 | 2 | −2 · 47 |
1
| 2947 · 81 | 9 |
Diagnostic Delay2 | 8% | 0 · 5% | −0 · 11 | 4 | 0 · 02 | 4 | −0 · 27 | 4 | 132 · 69 | 4 | |
Loss to follow up during Diagnosis | 25% | 14% | −0 · 45 | 2 | 0 · 10 | 3 | −0 · 60 | 3 | 710 · 63 | 8 | |
DOTS Expansion for Treatment | Incorrect Treatment | 79% | 13% | 0 · 00 | 6 | 1 · 98 |
1
| −1 · 54 | 2 | 363 · 20 | 7 |
Non specific DOTS Expansion (NTP Strengthening) | Access Government Facility | 94 · 5% | 97 · 5% | −0 · 09 | 5 | 0 · 02 | 4 | −0 · 12 | 6 | 164 · 65 | 5 |
HIV/ ART therapy programmes | HIV/TB Death rate | 12% | 10% | 0 · 00 | 6 | 0 · 00 | 6 | 0 · 00 | 8 | 0 · 00 | 2 |
HIV/TB Relapse rate | 16% | 1% | 0 · 00 | 6 | 0 · 00 | 6 | 0 · 00 | 8 | 0 · 00 | 2 | |
HIV/TB Reactivation rate | 3 · 4% | 2% | 0 · 00 | 7 | 0 · 01 | 5 | 0 · 05 | 9 | −142 · 43 |
1
| |
MDR-TB related interventions | DST performed | 20% | 50% | 0 · 00 | 6 | 0 · 02 | 4 | −0 · 03 | 7 | 232 · 19 | 6 |
Loss to follow up during MDR Treatment | 22% | 11% | 0 · 00 | 6 | 0 · 00 | 6 | 0 · 00 | 8 | 10 · 11 | 3 |
Category of intervention | Scenario | Primary active cases arising in cohort over 20 years1 | Total projected outcomes related to the primary active cases | |||
---|---|---|---|---|---|---|
Death during diagnosis and treatment phase | Cure due to treatment | Secondary cases generated from primary cases | Health system costs | |||
Baseline | 15 · 28 | 10 · 05 | 0 · 62 | 22 · 99 | $5,238 · 87 | |
General Health System Interventions | Improved diagnosis to detect 100% of TB cases in public sector (DS and MDR) | 15 · 28 | 7 · 67 | 1 · 57 | 17 · 07 | $12,292 · 55 |
Above & improved treatment to achieve 100% cure for DS in public sector | 15 · 28 | 4 · 96 | 8 · 60 | 12 · 22 | $12,354 · 14 | |
Above & reduced loss to follow up in public sector | 15 · 28 | 2 · 70 | 11 · 53 | 7 · 23 | $16,351 · 62 | |
MDR-TB related interventions | Above & Improve DST coverage to 100% | 15 · 28 | 2 · 59 | 11 · 72 | 6 · 96 | $18,441 · 46 |
Above & Improved treatment coverage so that all MDR cases diagnosed get standard MDR therapy | 15 · 28 | 2 · 07 | 12 · 61 | 5 · 66 | $27,327 · 96 | |
Above & New MDR drugs so treatment outcomes are as good as drug sensitive TB cases | 15 · 28 | 1 · 85 | 13 · 11 | 5 · 41 | $28,513 · 34 |
Interventions | Specific parameter change1 | Primary active cases arising in cohort over 20 years3 | Total projected outcomes related to the primary cases | |||||
---|---|---|---|---|---|---|---|---|
Parameter | Pre | Post | Death during diagnosis and treatment phase | Cure due to treatment | Secondary cases generated from primary cases | Health system cost | ||
Baseline | - | - | - | 69.82 | 47.34 | 2.40 | 106.05 | $2,818.01 |
Community Education | Patient delay2 | 11% | 6% | 69.82 | 45.97 | 2.51 | 104.24 | $2,955.56 |
DOTS expansion for diagnosis | Incorrect Diagnostic Test | 60% | 35% | 69.82 | 39.57 | 3.92 | 94.82 | $4,075.36 |
Diagnostic Delay2 | 8% | 0.5% | 69.82 | 46.29 | 2.54 | 104.44 | $2,942.14 | |
Loss to follow up during diagnosis | 25% | 14% | 69.82 | 45.47 | 2.76 | 103.35 | $3,121.12 | |
DOTS Expansion for Treatment | Incorrect Treatment | 79% | 13% | 69.82 | 47.34 | 10.00 | 99.21 | $2,920.66 |
Non specific DOTS Expansion (NTP Strengthening) | Access Government Facility | 94.5% | 97.5% | 69.82 | 46.96 | 2.47 | 105.50 | $2,906.57 |
HIV/ ART therapy programmes | HIV/TB Death rate | 12% | 10% | 69.82 | 47.34 | 2.45 | 106.05 | $2,818.01 |
HIV/TB Relapse rate | 16% | 1% | 69.82 | 47.34 | 2.70 | 105.93 | $2,818.01 | |
HIV/TB Reactivation rate | 3.4% | 2% | 57.11 | 39.55 | 2.01 | 86.58 | $2,326.66 | |
MDR-TB related interventions | DST performed | 20% | 50% | 69.82 | 47.34 | 2.41 | 106.02 | $2,986.38 |
Loss to follow up during MDR Treatment | 22% | 11% | 69.82 | 47.34 | 2.40 | 106.05 | $2,819.07 |
General intervention | Specific parameter changed1 | Projected changes in outcomes related to the primary active cases | |||||
---|---|---|---|---|---|---|---|
Parameter | Pre | Post | Death during diagnosis and treatment phase | Cure due to treatment | Secondary cases generated from primary cases | Health system costs | |
Baseline outcomes | - | - | - | 47.34 | 2.40 | 106.05 | $2,818.01 |
Community Education | Patient delay2 | 11% | 6% | −1.37 | 0.11 | −1.82 | 137.55 |
DOTS expansion for diagnosis | Incorrect Diagnostic Test | 60% | 35% | −7.77 | 1.52 | −11.23 | 1257.35 |
Diagnostic Delay2 | 8% | 0.5% | −1.05 | 0.14 | −1.61 | 124.13 | |
Drop out during Diagnosis | 25% | 14% | −1.87 | 0.37 | −2.71 | 303.11 | |
DOTS Expansion for Treatment | Incorrect Treatment | 79% | 13% | 0.00 | 7.61 | −6.84 | 102.65 |
Non specific DOTS Expansion (NTP Strengthening) | Access Government Facility | 94.5% | 97.5% | −0.38 | 0.08 | −0.56 | 88.57 |
HIV/ ART therapy programmes | HIV/TB Death rate | 12% | 10% | 0.00 | 0.05 | 0.00 | 0.00 |
HIV/TB Relapse rate | 16% | 1% | 0.00 | 0.30 | −0.12 | 0.00 | |
HIV/TB Reactivation rate | 3.4% | 2% | −7.79 | −0.39 | −19.47 | −491.35 | |
MDR-TB related interventions | DST performed | 20% | 50% | 0.00 | 0.02 | −0.03 | 168.37 |
Loss to follow up during MDR Treatment | 22% | 11% | 0.00 | 0.00 | 0.00 | 1.06 |