Table 2.
Values used in one-way and probabilistic sensitivity analyses
| Variable | Base case (mean value) | One-way sensitivity analysis | Probabilistic sensitivity analysis | ||||
|---|---|---|---|---|---|---|---|
| Lower bound | Upper bound | Distribution | SD/range | Notes | |||
| Costs (THB) | |||||||
| Vaccination costs per course | 790 | 672 | 909 | – | – | Not included in the PSA | |
| Direct medical costs | |||||||
| Homecare-RVGE | 174 | 148 | 200 | Gamma | 26.07 | SD assumed to be 15% of the mean | |
| Outpatient-RVGE | 759 | 645 | 873 | Gamma | 113.83 | ||
| Inpatient-RVGE | 4153 | 3530 | 4776 | Gamma | 622.94 | ||
| Direct non-medical costs | |||||||
| Transportation costs | |||||||
| Outpatient-RVGE | 93 | 56 | 148 | Gamma | 4.39 | SD based on reported standard error from Riewpaiboon et al. [60] | |
| Inpatient-RVGE | 112 | 75 | 148 | Gamma | 8.70 | ||
| Meal costs | |||||||
| Outpatient-RVGE | 41 | 18 | 69 | Gamma | 2.23 | ||
| Inpatient-RVGE | 52 | 35 | 69 | Gamma | 4.40 | ||
| Daily productivity loss of a caregiver | 348 | 296 | 400 | Gamma | 52.15 | SD assumed to be 15% of the mean | |
| Duration of RVGE (days) | |||||||
| Homecare-RVGE | 3 | 2 | 5 | Binomial | N/A | Distributions approximated based on a binomial distribution with 100,000 trials, with a probability that leads to the expected value to be the base case value | |
| Outpatient-RVGE | 3 | 2 | 5 | Binomial | |||
| Inpatient-RVGE | 4 | 4 | 5 | Binomial | |||
| Probability of RVGE incidence (%) | |||||||
| Homecare-RVGE | |||||||
| 0–1 years old | 1.1 | 0.9 | 1.2 | Beta | 0.16 | SD assumed to be 15% of the mean | |
| 1–2 years old | 1.2 | 1.0 | 1.4 | Beta | 0.18 | ||
| 2–3 years old | 0.6 | 0.5 | 0.7 | Beta | 0.09 | ||
| 3–4 years old | 0.4 | 0.4 | 0.5 | Beta | 0.06 | ||
| 4–5 years old | 0.3 | 0.3 | 0.4 | Beta | 0.05 | ||
| Outpatient-RVGE | |||||||
| 0–1 years old | 3.2 | 2.8 | 3.7 | Beta | 0.49 | SD assumed to be 15% of the mean | |
| 1–2 years old | 3.7 | 3.1 | 4.2 | Beta | 0.55 | ||
| 2–3 years old | 1.8 | 1.6 | 2.1 | Beta | 0.28 | ||
| 3–4 years old | 1.3 | 1.1 | 1.4 | Beta | 0.19 | ||
| 4–5 years old | 0.9 | 0.8 | 1.1 | Beta | 0.14 | ||
| Inpatient-RVGE | |||||||
| 0–1 years old | 1.1 | 0.9 | 1.2 | Beta | 0.16 | SD assumed to be 15% of the mean | |
| 1–2 years old | 3.2 | 2.7 | 3.6 | Beta | 0.48 | ||
| 2–3 years old | 1.7 | 1.4 | 2.0 | Beta | 0.26 | ||
| 3–4 years old | 1.2 | 1.0 | 1.4 | Beta | 0.18 | ||
| 4–5 years old | 0.7 | 0.6 | 0.8 | Beta | 0.10 | ||
| Under-5 years old RVGE-related death | 116.5a | 106.3 | 126.8 | Normal | 0.15 | Mean and SD calculated from the reported lower limit and upper limit of 3.1 and 3.7 per 100,000 children < 5 years old as 95% confidence interval | |
| Utility | |||||||
| Homecare-RVGE | 0.685 | 0.582 | 0.788 | Beta | 0.015 | Based on the reported SD in Rochanathimoke et al. [65] | |
| Outpatient-RVGE | 0.660 | 0.561 | 0.759 | Beta | 0.106 | ||
| Inpatient-RVGE | 0.591 | 0.502 | 0.680 | Beta | 0.124 | ||
| Health-adjusted life expectancy at birth (years) | 66.3 | 56.4 | 76.2 | Normal | 9.95 | SD assumed to be 15% of the mean | |
| Vaccination coverage (%) | 99.0 | 84.0 | 100.0 | – | – | Not included in the PSA | |
| Health outcomes discount rate (%) | 3.0 | 0.0b | 6.0b | – | – | Not included in the PSA | |
| Vaccine effectiveness | |||||||
| Vaccine effectiveness in 0–1 years old (%) | |||||||
| Homecare-RVGE | 70.0 | 53.5 | 81.3 | Beta | 53.5–81.3 | Based on 95% confidence interval reported by Li et al. [46] | |
| Outpatient-RVGE | 70.0 | 53.5 | 81.3 | Beta | 53.5–81.3 | ||
| Inpatient-RVGE | 85.7 | 37.9 | 98.4 | Beta | 37.9–98.4 | ||
| RVGE-related death | 98.4 | 83.6 | 100.0 | Beta | 0.85 | Distribution parameters based on the mean as the base case and the upper bound being bounded by 100%, with the resulting estimated SD as shown | |
| Decrease in vaccine effectiveness from 0–1 to 1–2 years old (%) | |||||||
| Homecare-RVGE | 34.9 | 29.6 | 40.1 | Beta | 5.23 | SD assumed to be 15% of the mean | |
| Outpatient-RVGE | 34.9 | 29.6 | 40.1 | Beta | 5.23 | ||
| Inpatient-RVGE | 16.2 | 13.8 | 18.7 | Beta | 2.43 | ||
| RVGE-related death | 1.3 | 1.1 | 1.5 | Beta | 0.20 | ||
HTA health technology assessment, N/A not applicable, PSA probabilistic sensitivity analysis, RVGE rotavirus gastroenteritis
SD standard deviation, THB Thai baht
aMortality of 3.4 per 100,000 children < 5 years old was used to calculate this figure
bDiscount rate varied from 0.0% to 6.0% as recommended by the Thai HTA guidelines [67]