Table 3.
Cost input values and sources applied in base case, sensitivity and scenario analyses
| Base value | Lower bound for DSA | Upper bound for DSA | Standard error for PSA | |
|---|---|---|---|---|
| Direct medical costs | ||||
| Costs per HZ case | ||||
| Without any complications | 38,471 | 35,575 | 41,367 | 1478 |
| With PHN | 127,079 | 90,164 | 163,994 | 18,834 |
| With non PHN-related complications | 72,789 | 37,482 | 108,096 | 18,014 |
| Source | (11, 25, 34)a | (11)a | (11)a | |
| Vaccination costs | ||||
| RZV vaccine price per dose | 12,960 | 10,800b | 16,200b | – |
| Source | Assumption c | Assumption | Assumption | – |
| Administration cost per dose | 3424 | 2568b | 4280b | – |
| Source | Assumption d | − 25%: Assumption | + 25%: Assumption | – |
| Adverse event costs | ||||
| Local/general | 0 | – | – | – |
| Outpatient | 3957.5 | – | – | – |
| ER | 8757.5 | – | – | – |
| Hospitalization | 225,750 | – | – | – |
| Source | Assumption e | NA | NA | – |
| Indirect costs | ||||
| Costs per HZ case | ||||
| Without PHN | ||||
| 50–59 YOA | 17,747 | – | – | – |
| 60–69 YOA | 15,128 | 11,346 | 18,910 | 1929 |
| 70–79 YOA | 11,892 | 8919 | 14,865 | 1517 |
| ≥ 80 YOA | 15,115 | 11,336 | 18,894 | 1928 |
| With PHN | ||||
| 50–59 YOA | 57,662 | – | – | – |
| 60–69 YOA | 32,733 | 24,550 | 40,916 | 4175 |
| 70–79 YOA | 20,297 | 15,223 | 25,371 | 2589 |
| ≥ 80 YOA | 19,046 | 14,285 | 23,808 | 2429 |
| Source | Derived from (11)f | − 25%: Assumption | + 25%: Assumption | |
DSA deterministic sensitivity analysis, ER emergency room, HZ herpes zoster, PHN postherpetic neuralgia, PSA probabilistic sensitivity analysis, RZV recombinant zoster vaccine, YOA years of age
aNakamura et al. reported HZ-related costs for patients with HZ without any complications, with PHN, and with non-pain complications in a prospective cohort study [11]. The costs were adjusted by hospitalization rate reported by Sato et al. [25]. In addition, the cost for patients with PHN was converted into the annual cost by adding the PHN treatment cost for 3 months (= 95,809/6 months × 3/6 months × 50%) reported by Honda et al. [34]. Calculated a range from the standard error of the data reported by Nakamura et al. [11]
bThis input was varied in one-way sensitivity analysis but was held at its base value(s) in probabilistic sensitivity analysis
cAssumed the price from the vaccination cost comparable to that used in the cost-effectiveness analysis in the US [21] and Germany [20]. Cost input was the price including 8% consumption tax
dCalculated based on medical fee point scheme in 2016; (2820 for initial visit + 200 for biologics + 150 for injection) × 1.08 = ¥3424
eAssumed based on medical fee point scheme in 2016 according to expert opinion; no healthcare resource utilization for local/general; 2820 for initial visit + 680 for prescription + (15.9 (Sodium Loxoprofen) + 14.6 (Rebamipide)) × 15T = ¥3957.5 for Outpatient; 4800 for visit between 22:00 and 6:00 + AE cost for outpatient = ¥8757.5 for ER. Assumed based on diagnosis procedure combination (DPC) point scheme in 2016; DPC code of 080100 (drug eruption) with admission for median duration, 25,940 × 5 + 19,210 × 5 = ¥225,750 for Hospitalization. The model calculated a weighted adverse event (AE) cost per dose based on the incidence of the four AEs and the costs per event. The weighted cost per dose was varied by + 100% and − 50% in sensitivity analysis, so no ranges were used for the individual costs per AE
fIndirect costs include productivity loss of patients and their caregivers. The productivity loss of patients was calculated based on the number of visits and admission days (Table S3). Assumed to be a range of ± 25% in sensitivity analysis