Background
Methods
Study design
Epidemiological data
Baseline HIV incidence
HIV/AIDS progression
Change in risk behaviors
Costs data
Health outcome variables
Uncertainty analysis
Parameters | Distribution | Mean | SE | References |
---|---|---|---|---|
Yearly discount rate (%)
| ||||
Costs (range) | 3 (0-6) | [17] | ||
Outcome (range) | 3 (0-6) | [17] | ||
Transition probabilities
| ||||
Probabilities of HIV infection classified by risk group
| ||||
Annual incidences of HIV infected in general population aged 18 years | Beta | 0.001 | [18] | |
Annual incidences of HIV infection in FSW | Beta | 0.022 | 0.016 | [19] |
Annual incidences of HIV infection in IDU | Beta | 0.034 | 0.002 | [20] |
Annual incidences of HIV infection in MSM | Beta | 0.055 | 0.010 | [21] |
Annual incidences of HIV infection in male conscripts | Beta | 0.002 | 0.001 | [19] |
Transition probabilities of HIV positive with asymptomatic state
| ||||
Annual progression risk from asymptomatic to symptomatic state | Beta | 0.865 | 0.047 | [46] |
Annual death risk of asymptomatic state | Beta | 0.058 | 0.008 | [22] |
Transition probabilities of HIV positive with symptomatic state
| ||||
Annual probability to progress from HIV to AIDS | Beta | 0.087 | 0.0004 | |
Constant in survival analysis for baseline hazard | Lognormal | -8.38 | 1.44 | [24] |
CD4 coefficient in survival analysis for baseline hazard | Lognormal | -0.01 | 0.001 | [24] |
Ancillary parameter in Weibull distribution | Lognormal | 0.04 | 0.19 | [24] |
Average CD4 of patients (#patients=234) | Lognormal | 321.44 | 9.46 | [24] |
Transition probabilities of AIDS state to death
| ||||
Constant in survival analysis for baseline hazard | Lognormal | -4.81 | 0.86 | [23] |
Age coefficient in survival analysis for baseline hazard | Lognormal | -0.04 | 0.02 | [23] |
CD4 coefficient in survival analysis for baseline hazard | Lognormal | -0.02 | 0.00 | [23] |
Ancillary parameter in Weibull distribution | Lognormal | -0.33 | 0.11 | [23] |
Average CD4 of patients (#patients=646) | Gamma | 81.01 | 2.67 | [23] |
Transition probability of switching from first-line to second-line ART regimen
| ||||
Constant in survival analysis for baseline hazard | Lognormal | -6.17 | 0.52 | [23] |
CD4base coefficient in survival analysis for baseline hazard | Lognormal | 0.003 | 0.001 | [23] |
Age coefficient in survival analysis for baseline hazard | Lognormal | 0.0313 | 0.0113 | [23] |
Ancillary parameter in Weibull distribution | Lognormal | -0.49 | 0.07 | [23] |
Transition probability of switching from second-line to third-line ART regimen
| ||||
Constant in survival analysis for baseline hazard | Lognormal | -10.29 | 1.27 | [23] |
Age coefficient in survival analysis for baseline hazard | Lognormal | 0.06 | 0.02 | [23] |
Ancillary parameter in Weibull distribution | Lognormal | 0.01 | 0.14 | [23] |
Parameters | Distribution | Mean | SE | References |
---|---|---|---|---|
Costs of prevention program
| ||||
Annual costs of existing prevention programs | Gamma | 24 | ||
Cost of HIV vaccine per course | Gamma | 3,500 | [12] | |
Individual cost of community engagement | Gamma | 937* | ||
Cost of HIV screening (ELISA) for vaccine acceptance | Gamma | 125 | [47] | |
Cost of pre-counselling for all vaccinations | Gamma | 141 | [47] | |
Cost of post-counselling for vaccine acceptance | Gamma | 58 | [47] | |
Costs of treatment program
| ||||
Costs of asymptomatic treatment
| ||||
Laboratory cost for asymptomatic patient | Gamma | 8,155 | [29] | |
Hospital service cost of asymptomatic patient | Gamma | 2,502 | [29] | |
OPD cost of asymptomatic patient | Gamma | 2,502 | [29] | |
Costs of symptomatic treatment
| ||||
Lab test cost for symptomatic patient | Gamma | 8,931 | [29] | |
Opportunity infection treatment cost of symptomatic patient | Gamma | 4,739 | [29] | |
Hospital service cost of symptomatic patient | Gamma | 9,104 | [29] | |
OPD cost of symptomatic patient | Gamma | 2,502 | [29] | |
IPD cost of symptomatic patient | Gamma | 6,227 | [29] | |
Costs of AIDS treatment
| ||||
Opportunity infection treatment cost of AIDS patient | Gamma | 4,739 | [29] | |
Hospital service cost of AIDS patient | Gamma | 9,104 | [29] | |
OPD cost of AIDS patient | Gamma | 2,502 | [29] | |
IPD cost of AIDS patient | Gamma | 6,227 | [29] | |
Annual drug costs of the first-line ART regimens (mg): | Gamma | 8,184†
| 1,858†
| |
1. d4T(30)+3TC(150)+NVP(200) or | ||||
2. d4T(30) + 3TC(150) + EFV (600) or | ||||
3. AZT(100/200/250/300)+3TC(150)+NVP(200) or | ||||
4. AZT(100/200/300)+3TC(150)+EFV(600) | ||||
Annual drug costs of the second-line ART regimens (mg): | Gamma | 32,478†
| 5,772†
| |
1. ddI(250)+3TC(150)+NVP(200) or | ||||
2. ddI(250)+3TC(150)+EFV(600) or | ||||
3. TDF(300)+3TC(150)+NVP(200) or | ||||
4. TDF(300)+3TC(150/300)+EFV(600) | ||||
Annual drug costs of the third-line ART regimens (mg): | Gamma | 15,682†
| 2,080†
| |
1. AZT(100/200/300)+3TC(150)+Boosted PIs‡ or | ||||
2. d4T(30)+3TC(150)+Boosted PIs‡ or | ||||
3. TDF(300)+3TC(150)+Boosted PIs‡ or | ||||
4. ddI(250)+3TC(150)+Boosted PIs‡ or | ||||
5. AZT(100/200/300)+ddI(250)+Boosted PIs‡ or | ||||
6. AZT(100/200/300)+TDF(300)+Boosted PIs‡ or | ||||
7. AZT(100/200/300)+3TC(150)+TDF(300)+Boosted PIs‡
| ||||
Annual costs of lab test of first-line ART regimen in the first year | Gamma | 7,671 | [48] | |
Annual costs of lab test of first-line ART regimen in subsequence years | Gamma | 4,210 | [48] | |
Annual costs of lab test of the second-line ART regimen | Gamma | 4,140 | [48] | |
Annual costs of lab test of the third-line ART regimen | Gamma | 4,163 | [48] |
Parameters | Distribution | Mean | SE | References |
---|---|---|---|---|
Utility parameters
| ||||
Utility of HIV negative | 1 | |||
Utility of asymptomatic patients | Beta | 0.86 | 0.01 | [24] |
Utility of symptomatic patients | Beta | 0.80 | 0.01 | [24] |
Utility of AIDS patients | Beta | 0.76 | 0.01 | [24] |
Characteristics of HIV vaccine
| ||||
Vaccine efficacy | Gamma | 31% | 13% | [11] |
Increased incidences of HIV infection compared to baseline due to the change of risk behaviors | Gamma | 20%* | 20%* | |
Duration of booster doses (year) | Gamma | 10* | 10* |
Results
Cost-utility analysis
HIV vaccination program | Existing prevention programs | ICER | |||
---|---|---|---|---|---|
Costs (THB) | QALY | Costs (THB) | QALY | THB per QALY gained* | |
General population
| |||||
aged 18 years old | 12,900 | 25.73 | 5,490 | 25.68 | 157,000 |
FSW
| |||||
aged 29 years old | 47,300 | 23.46 | 46,800 | 23.25 | 2,840 |
IDU
| |||||
aged 26 years old | 53,900 | 13.03 | 62,400 | 12.61 | Dominated†
|
MSM
| |||||
aged 26 years old | 243,000 | 16.51 | 245,000 | 16.27 | Dominated†
|
Male conscript
| |||||
aged 21 years old | 11,400 | 23.80 | 4,570 | 23.78 | 326,000 |
Uncertainty analysis
One-way sensitivity analysis
Vaccine prices (THB) being cost-effective at a WTP threshold 100,000 THB per QALY gained | |||||||||
---|---|---|---|---|---|---|---|---|---|
Duration of protection | Lifetime | 10 years 3 boosters with full course†
| 5 years 6 boosters with full course†
| ||||||
Vaccine efficacy | 30% | 50% | 70% | 30% | 50% | 70% | 30% | 50% | 70% |
Risk behavior changed* | |||||||||
General population aged 18 years old
| |||||||||
Unchanged | 4,400 | 7,900 | 12,000 | 1,100 | 2,700 | 4,300 | - | 730 | 1,600 |
Increased 10% | 2,400 | 6,500 | 11,000 | 210 | 2,000 | 3,900 | - | 380 | 1,400 |
Increased 20% | - | 4,500 | 9,600 | - | 1,100 | 3,400 | - | - | 1,100 |
Increased 30% | - | 2,000 | 8,100 | - | 23 | 2,700 | - | - | 760 |
General population aged 30 years old
| |||||||||
Unchanged | - | 410 | 1,100 | - | - | - | - | - | - |
Increased 10% | - | 180 | 960 | - | - | - | - | - | - |
Increased 20% | - | - | 780 | - | - | - | - | - | - |
Increased 30% | - | - | 550 | - | - | - | - | - | - |
FSW aged 29 years old
| |||||||||
Unchanged | 52,000 | 85,000 | 120,000 | 23,000 | 38,000 | 54,000 | 12,000 | 20,000 | 29,000 |
Increased 10% | - | 37,000 | 92,000 | - | 16,000 | 41,000 | - | 8,000 | 22,000 |
Increased 20% | - | - | 59,000 | - | - | 26,000 | - | - | 14,000 |
Increased 30% | - | - | 22,000 | - | - | 9,500 | - | - | 4,500 |
IDU aged 26 years old
| |||||||||
Unchanged | 57,000 | 96,000 | 140,000 | 35,000 | 58,000 | 82,000 | 21,000 | 34,000 | 48,000 |
Increased 10% | 22,000 | 69,000 | 120,000 | 14,000 | 42,000 | 73,000 | 7,600 | 25,000 | 43,000 |
Increased 20% | - | 45,000 | 110,000 | - | 28,000 | 64,000 | - | 16,000 | 38,000 |
Increased 30% | - | 24,000 | 93,000 | - | 15,000 | 56,000 | - | 8,400 | 33,000 |
MSM aged 26 years old
| |||||||||
Unchanged | 170,000 | 310,000 | 500,000 | 100,000 | 170,000 | 250,000 | 59,000 | 98,000 | 140,000 |
Increased 10% | - | 40,000 | 260,000 | - | 24,000 | 140,000 | - | 14,000 | 82,000 |
Increased 20% | - | - | 31,000 | - | - | 19,000 | - | - | 11,000 |
Increased 30% | - | - | - | - | - | - | - | - | - |
Military male conscript aged 21 years old
| |||||||||
Unchanged | 2,200 | 5,500 | 8,900 | 150 | 1,600 | 3,100 | - | 160 | 1,000 |
Increased 10% | - | 3,100 | 7,500 | - | 560 | 2,500 | - | - | 650 |
Increased 20% | - | 320 | 5,800 | - | - | 1,800 | - | - | 240 |
Increased 30% | - | - | 3,800 | - | - | 850 | - | - | - |