Table 2.
Parameters including base values, range, distributions, and sources. All costs are in 2015 United States Dollars
| Parameter | Base value | Range | Source |
|---|---|---|---|
| Prevalence of HBsAg | 0.062 | 0.057–0.067 | [21] with 95% CI |
| Prevalence of HBeAg carrier if HBsAg+ | 0.307 | 0.273–0.341 | 30.7% of the HBsAg positive women [21] |
| Prevalence of HBV DNA > 200,000 IU per mL if HBsAg+ | 0.252 | 0.203–0.301 | 82% of the HBeAg positive women [22] |
| Probability of attending ANC at least 7 days before delivery can receive additional testing | 0.946 | 0.944–0.998 | SMRU data with 95% CI |
| Probability of attending ANC at least 3 m before delivery so can receive TDF | 0.663 | 0.660–0.666 | SMRU data with 95% CI |
| Proportion of women receiving TDF that would receive 5 m of treatment | 0.720 | 0.716–0.724 | SMRU data with 95% CI |
| Probability of clinic delivery after attending ANC | 0.888 | 0.850–0.910 | [21] SMRU data with 95% CI |
| Probability that infants birthed at home after attending ANC will receive HBV birth dose vaccine at the clinic (present within 12 h) | 0.272 | 0.264–0.280 | SMRU data with 95% CI |
| Probability of HBV perinatal infection for HBsAg+, HBeAg- mothers without vaccinations | 0.110 | 0.070–0.150 | [23–26] with low from [24] and high from [23] |
| Probability of HBV perinatal infection for HBeAg+ mothers without vaccinations | 0.840 | 0.790–0.900 | [23–25, 27] with low from [25] and high from [26] |
| Probability of HBV perinatal infection for HBsAg+, HBeAg- mothers with vaccinations | 0.038 | 0.031–0.045 | [28] |
| Probability of HBV perinatal infection for HBeAg+ mothers with vaccinations | 0.210 | 0.143–0.278 | [28–30] |
| Probability of HBV perinatal infection for HBsAg+, HBsAg- mothers with vaccinations and HBIG | 0.010 | 0.001–0.030 | [28] |
| Probability of HBV perinatal infection for HBeAg+ mothers with vaccinations and HBIG | 0.180 | 0.100–0.260 | [4] |
| Probability of HBV perinatal infection for HBsAg+, HBsAg- mothers with TDF, no HBIG | 0.0025 | 0.0005–0.0055 | Assumed based on midpoints of HBIG transmissions |
| Probability of HBV perinatal infection for HBeAg+ mothers with less than five months of TDF | 0.0500 | 0.0070–0.0930 | Assumed based on midpoints of HBIG transmissions |
| Probability of HBV perinatal infection for HBeAg+ mothers with five months of TDF | 0.025 | 0.0001–0.050 | Assumed based on lower points of HBIG transmissions |
| Probability of HBV perinatal infection for HBsAg+, HBeAg- mothers with TDF and vaccinations | 0.0013 | 0.0003–0.0028 | Assumed based on midpoints of TDF |
| Probability of HBV perinatal infection for HBeAg+ mothers with TDF and vaccinations | 0.0128 | 0.0025–0.0280 | Assumed based on midpoints of TDF |
| Probability of HBV perinatal infection for HBsAg+, HBeAg- mothers with TDF, vaccinations and HBIG | 0.0003 | 0.00003–0.0006 | Assumed based on midpoints of TDF and vaccinations |
| Probability of HBV perinatal infection for HBeAg+ mothers with TDF, vaccinations and HBIG | 0.0005 | 0.0003–0.0013 | Assumed based on midpoints of TDF and vaccinations |
| Probability of having a hepatic flare after stopping TDF | 0.500 | 0.352–0.648 | [31] |
| Probability that the hepatic flare requires treatment | 0.308 | 0.163–0.453 | [31] |
| Sensitivity of the RDT for HBsAg | 0.980 | 0.631–1.000 | Assumed based on [21] |
| Specificity of the RDT for HBsAg | 0.989 | 0.969–1.000 | Assumed based on [21] |
| Sensitivity of the confirmatory test for HBeAg | 1.000 | 0.900–1.000 | [32] with assumed range |
| Specificity of the confirmatory test for HBeAg | 1.000 | 0.900–1.000 | [32] with assumed range |
| Sensitivity of HBV DNA PCR | 0.953 | 0.700–1.000 | [33] with assumed range |
| Specificity of HBV DNA PCR | 0.997 | 0.700–1.000 | [33] with assumed range |
| Cost of HBV vaccinations | 6.65 | 3.33–9.98 | SMRU records + 50%. Cost of single vaccination at birth plus three doses of HBV diphtheria tetanus and pertussis combined vaccine given at 2, 4 and 6 months |
| Cost of RDT for HBsAg | 1.3 | 0.65–1.96 | SMRU records + 50% |
| Cost of confirmatory test | 21.19 | 10.60–31.79 | SMRU records + 50% |
| Cost of a PCR test | 32.60 | 16.30 | SMRU records + 50% |
| Cost per dose of HBIG | 88.02 | 44.01–132.03 | SMRU records + 50% |
| Cost per month of TDF | 11.74 | 5.87–17.60 | TDF Thailand bought |
| Cost for hepatic flare monitoring | 6.85 | 3.42–10.27 | ALT, Creatine and phosphate tests, twice each. |
| Cost of a hepatic flare | 44.99 | 22.49–67.48 | TDF for three additional months, five ALT tests |
ALT Alanine aminotransferase, ANC antenatal care, CI Confidence interval, DNA Deoxyribonucleic acid, EGA estimated gestational age, HBV hepatitis B Virus, HBIG hepatitis B immunoglobulin, HBeAg hepatitis B envelope antigen, HBsAg hepatitis B surface antigen, TDF Tenofovir Disoproxil Fumarate, PCR Polymerase Chain Reaction, SMRU Shoklo Malaria Research Unit. Vaccinations, Birth dose and 3 follow up vaccinations