Table 3.

Key study outputs

Study	Population	Intervention and comparator	Net health benefits (per patient)*	Net costs (per patient)	Incremental cost-effectiveness ratio*	Headline results
Comparison of vaccination types
Baio et al 23†	Unknown risk aged ≥65	Adjuvanted vaccination vs standard vaccination	NR	−€1.95	Adjuvanted vaccine dominated standard vaccination (per death averted)	Adjuvanted vaccine was shown to be cost-effective against the standard vaccine.
Meier et al 24	Mixed risk aged ≥65 (48% high risk)	Quadrivalent influenza vaccination vs trivalent influenza vaccination	NR	NR	€11 751 per QALY	Quadrivalent vaccination is cost-effective compared with trivalent vaccination in the UK.
Piercy et al (2004)25	High-risk elderly people aged ≥65	Adjuvanted vaccination vs standard vaccination	0.003397 fewer ILI cases, 0.000043 deaths avoided and 0.000300 LYG	€1.31	€30 503 per death avoided and €6131 per LYG	Results were mixed according to the different scenarios for the strain of the influenza virus considered.
Comparison of vaccination strategies
Allsup et al 26	Low risk aged 65–74	Vaccination vs no intervention	0.000007 fewer deaths and 0.000044 additional QALYs	€ 5.37‡	€3 576 908 per death avoided, €4 59 350 per life-year gained and €5 72 305 per QALY gained	Influenza vaccination was judged not to be cost-effective in the low-risk elderly population.
Baio et al 23†	Unknown risk aged ≥65	Adjuvanted vaccination vs no intervention	NR	−€3.76	Adjuvanted vaccine dominated no intervention (per death averted)	Both vaccination types were cost-effective against no intervention.
		Standard vaccination vs no intervention	NR	−€1.91	Standard vaccine dominated no intervention (per death averted)
Brydak et al 29	Mixed risk aged ≥65 (50% high risk)	Reimbursed vaccination vs no intervention	NR	€22.61	€11 790 per QALY gained, €58 981 cost per death avoided and €6881 per life-year gained	Introducing public funding of influenza vaccination for people aged 65 and older to increase coverage was cost-effective compared with the status quo.
Lugner et al 30	Mixed risk aged ≥65 (73%–100% high risk)	Vaccination versus no intervention (Germany)	NR	€13.22	€1065 per QALY gained (direct costs) and dominant per QALY gained (indirect costs included)	In general, vaccination was shown to be a cost-effective strategy. Early vaccination strategies are more favourable with lower total costs and cost per QALY gained. The inclusion of indirect costs makes the early vaccination strategies dominant in all countries.
		Vaccination vs no intervention (UK)	NR	€17.19	€4621 per QALY gained (direct costs) and dominant per QALY gained (indirect costs included)
		Vaccination vs no intervention (Netherlands)	NR	€17.62	€1338 per QALY gained (direct costs) and dominant per QALY gained (indirect costs included)
Postma et al 28	Mixed risk aged ≥65 (35% high risk)	Vaccination vs no intervention	NR	NR	€2468 per LYG (all elderly people), €9355 per LYG (low risk) and dominant per LYG (high risk)	Population-wide influenza vaccination for elderly people was found to be cost-effective. More favourable results were estimated in the high-risk population.
Scuffham and West31	Unknown risk aged ≥65 or 60 (country differences)	Opportunistic vaccination vs no intervention (England)	0.547400 fewer morbidity days and 0.001040 LYG	−€1.89	Dominated per LYG gained	Vaccination strategies were cost-effective vs no intervention.
		Comprehensive vaccination vs no intervention (England)	1.065400 fewer morbidity days and 0.002020 LYG	−€0.84	Dominated per LYG
		Opportunistic vaccination vs no intervention (France)	0.822500 fewer morbidity days and 0.001470 LYG	€2.11	€1437 per LYG
		Comprehensive vaccination vs no intervention (France)	1.011300 fewer morbidity days and 0.001800 LYG	€6.53	€3623 per LYG
		Opportunistic vaccination vs no intervention (Germany)	0.479500 fewer morbidity days and 0.000780 LYG	€2.87	€3676 per LYG
		Comprehensive vaccination vs no intervention (Germany)	0.760200 fewer morbidity days and 0.001240 LYG	€8.69	€7016 per LYG

*Note that net benefit per person was calculated by the author where the total net benefits across the population and total population figures were provided by studies. This may mean that there appears to be differences between the incremental cost-effectiveness ratio value calculated by the study and the value calculated using the net benefit above, likely due to rounding differences.

†Note that the study by Baio et al ²³ directly compared vaccination types, as well as comparing both vaccination types to no vaccination.²³

‡Trial cost only reported (not actual modelled costs).

ILI, influenza-like illness; LYG, life-years gained; NR, not reported; QALY, quality-adjusted life-year.