Table 1. Study characteristics of included studies.
Source | Objective | Type | Based on | Currency | Analytic horizon | Dis-counting | Influenza outcome | Impact | Uncertainty analysis | Funding source |
---|---|---|---|---|---|---|---|---|---|---|
Aballéa et al.40 | Economic evaluation of lowering the age threshold in various countries for influenza vaccination from currently 60 or 65 y to all people aged 50 y and older | CUA | Model | Brazilian real | Not reported | Life expectancy in unadjusted life years and quality-adjusted life years (3% per annum) | ILI; minor complications; hospitalization for pneumonia and influenza, for other respiratory complications, and other complications; and deaths | QALY gained | One-way sensitivity/ threshold analysis and PSA | IVS International Task Force |
Chicaiza-Becerra et al.41 | Cost-effectiveness evaluation of implementing a vaccination program for health workers in contact with hospitalized oncological patients | CEA | Model | Colombian peso | Not reported | Not applicable | Days hospitalized for influenza-related complications | Cost-effectiveness ratio (additional days of hospitalization prevented) | One-way sensitivity analysis for different transmission probabilities | Not specifically mentioned |
Dayan et al.24 | To compare from the societal perspective the costs and benefits of a general influenza vaccination program in high-risk children with no vaccination | CEA | Model | US dollars | 12 mo | Not applicable | Influenza outcomes including outpatient visits, otitis media and hospitalization | influenza episodes averted | One-way sensitivity/ threshold analysis and PSA | Not specifically mentioned |
Gutiérrez et al.43 | Estimation of costs and health outcomes achievable by vaccination of people aged 65 y and older | CEA | Model | Mexican peso | 5 mo | Costs per life year saved by different discount rates (3% assumed as bases, estimates provided for 0%, 5%, 10%) | Pneumonia-and influenza-associated deaths and cases | Life years saved, costs per life year saved | PSA | National public health institute |
Porras-Ramirez et al.42 | Evaluating the economic value of influenza vaccination of infants aged below 2 y and elderly aged 65 y and above | CEA | Model | US dollars | 1 y | 3% discounting | Among below 2 y old: annual number of cases of ARI, medical visits, hospitalizations and deaths from ARI Among 65 y and above: annual number of deaths and hospitalizations due to cardiocirculatory diseases. |
ARI-related hospitalization prevented, direct costs saved annually | Univariate sensitivity analysis | Ministry for social protection |
Gao et al.46 | To assess cost benefit of vaccinating employers insured under a social-health program; results extrapolated to the whole population of the city | CBA | RCT | Chinese yuan | 5 y | Not reported | Respiratory system diseases and other chronic diseases such as cardiovascular diseases | Respiratory system disease and cardio-vascular diseases related hospitalization costs averted | Sensitivity analysis for vaccination coverage | Not specifically mentioned |
Liu et al.47 | To compare vaccinated with non-vaccinated elderly and estimate effectiveness. | CBA | RCT | Chinese yuan | 6 mo | Not reported. | ILI incidence and related chronic diseases such as common cold, other respiratory tract or chronic disease such as diabetes | Medical consultations and number of hospital day-related costs averted | None performed | Not specifically mentioned |
Praditsuwan et al.44 | To determine cost effectiveness of influenza vaccination in the Thai elderly living in an urban community compared with placebo | CEA | RCT | Thai baht | Not reported | Not reported | ILI, upper respiratory infection, and serologically confirmed influenza. | Unclear | None performed | National Research Council of Thailand |
Wongsurakiat et al.45 | To determine cost- effectiveness and cost-benefit of influenza vaccination in COPD patients compared with placebo | CEA | RCT | Thai baht | 16–18 mo | Not applicable | Influenza-like outcomes including episodes of acute respiratory illness | Acute respiratory infection episodes averted | None performed | National Research Council of Thailand |
CBA, cost-benefit analysis; CUA, cost-utility analysis; CEA, cost-effectiveness analysis; QALY, quality adjusted life years; PSA, probabilistic sensitivity analysis; ILI, influenza-like illness.