Table 1.
Data inputs
| Description (units) | Distribution Type | Mean | Standard deviation or range | Source |
|---|---|---|---|---|
| Costs ($US) | ||||
| Annual vaccine | Point estimate | 20 | – | 11, 35 |
| Influenza treatment | ||||
| Outpatient visit | ||||
| Pediatric outpatient visit | Point estimate | 74·90 | – | 36 |
| Adult outpatient visit | Triangular | 104·77 | 69·14–140·39 | 37 |
| Elderly outpatient visit | Triangular | 155·92 | 118·39–193·44 | 37 |
| Hospitalization | ||||
| Age 1–4 | Gamma | 5992 | 515 | 38 |
| Age 5–9 | Gamma | 5761 | 561 | 38 |
| Age 10–14 | Gamma | 8735 | 1231 | 38 |
| Age 15–17 | Gamma | 6559 | 816 | 38 |
| Age 18–44 | Gamma | 6506 | 461 | 38 |
| Age 45–64 | Gamma | 7580 | 759 | 38 |
| Age 65–84 | Gamma | 7568 | 234 | 38 |
| Age 85 and Over | Gamma | 7698 | 240 | 38 |
| General death | Triangular | 6921 | 5191–9025 | 39 |
| Treatment of vaccine side effects | Triangular | 0·79 | 0·70–3·93 | 11 |
| Median hourly wage | Point estimate | 15·57 | – | 35 |
| Durations | ||||
| Work hours per day | Point estimate | 8 | – | Assumption |
| Absenteeism from influenza (days) | Uniform | 3·2 | 1·5–4·9 | 40 |
| Time being sick from the flu | Uniform | 6 | 5–7 | 41, 42 |
| Time after having vaccine side effects | Uniform | 0·75 | 0·5–1 | 43 |
| Utilities (QALYs) | ||||
| One year of life | ||||
| Age 0–17 | Point estimate | 1 | – | 8 |
| Age 18–64 | Point estimate | 0·92 | – | 8 |
| Age 65 and Over | Point estimate | 0·84 | – | 8 |
| Influenza with no hospitalization | Triangular | 0·65 | 0·49–0·81 | 44, 45 |
| Influenza with hospitalization | Triangular | 0·50 | 0·38–0·63 | 44, 46 |
| Vaccine side effects | Triangular | 0·95 | 0·71–1·00 | 46 |
| Probabilities | ||||
| Clinical outcomes without vaccination | ||||
| Influenza throughout the year | Triangular | 0·125 | 0·05–0·2 | 7 |
| Outpatient visit given influenza | ||||
| Age 0–4 | Beta | 0·455 | 0·098 | 47 |
| Age 5–17 | Beta | 0·318 | 0·061 | 47 |
| Age 18–64 | Beta | 0·313 | 0·014 | 47 |
| Age 65 and over | Beta | 0·620 | 0·027 | 47 |
| Age 0–4 (high‐risk) | Beta | 0·910 | 0·250 | 47 |
| Age 5–17 (high‐risk) | Beta | 0·635 | 0·167 | 47 |
| Age 18–64 (high‐risk) | Beta | 0·625 | 0·118 | 47 |
| Age 65 and over (high‐risk) | Beta | 0·850 | 0·093 | 47 |
| Hospitalization given influenza | ||||
| Age 0–4 | Beta | 0·0141 | 0·0047 | 47 |
| Age 5–17 | Beta | 0·0006 | 0·0002 | 47 |
| Age 18–49 | Beta | 0·0042 | 0·0014 | 47 |
| Age 50–64 | Beta | 0·0193 | 0·0064 | 47 |
| Age 65 and over | Beta | 0·0421 | 0·0140 | 47 |
| Mortality given influenza | ||||
| Age 0–4 | Beta | 0·00004 | 0·00001 | 47 |
| Age 5–17 | Point estimate | 0·00001 | 47 | |
| Age 18–49 | Beta | 0·00009 | 0·00003 | 47 |
| Age 50–64 | Beta | 0·00134 | 0·00045 | 47 |
| Age 65 and over | Beta | 0·01170 | 0·00390 | 47 |
| Vaccine efficacy | Triangular | 0·45 | 0·56–0·68 | 7 |
| Vaccine side effects | Point estimate | 0·03 | – | 48 |