Table 1 Input parameters of the model

Demographic parameters

 Number of age-specific children [29]

Additional file 1: Tables S1–2

NA

 Proportion of age-specific children in the urban area [30]

Additional file 1: Tables S1–2

NA

 Proportion of age-specific high-risk children [31, 32]

Additional file 1: Table S3

NA

Epidemiologic parameters

 Symptomatic influenza rate [11]

 < 5 years: 0.0586 (0.0362–0.0976)

5–14 years: 0.0155 (0.0096–0.0256)

Beta

 Proportion of cases seeking healthcare among symptomatic cases [25]

Urban: 0.844 (0.6752–1)

Rural: 0.791 (0.6328–0.9492)

Beta

 Proportion of outpatient among seeking healthcare cases [33]

 < 5 years: 0.6976 (0.5581–0.8371)

5–14 years: 0.6579 (0.5263–0.7895)

NA

 Proportion of hospitalization among seeking healthcare cases [33]

 < 5 years: 0.0745 (0.0596–0.0894)

5–14 years: 0.0504 (0.0403–0.0605)

Beta

Proportion of complications and death

 Proportion of pneumonia [34, 35]

0.2017 (0.1614–0.2420)

Beta

 Proportion of neurologic disorders [34, 35]

0.0017 (0.0014–0.0020)

Beta

 Influenza-associated excess respiratory mortality [36]

Additional file 1: Table S5

Beta

 Odds ratio of influenza-related hospitalization in high-risk groups compared to low-risk groups [37]

3.39 (2.60–4.42)

Lognormal

 Odds ratio of influenza-related death in high-risk groups compared to low-risk groups [37]

2.04 (1.74–2.39)

Lognormal

 Duration of influenza episode [45]

Outpatient: 6.2 (5.0–7.4)

Hospitalization: 11.8 (9.4–14.2)

Normal

Vaccine related parameters

 Cost of vaccine

Children’s type: 4.56 (4.08–5.11)

Adults’ type: 6.66 (4.70–9.74)

Gamma

 Cost of administration [39]

3.52 (2.81–4.22)

Gamma

 Cost of parent’s time to obtain the influenza vaccine in urban and rural areas [39]

Additional file 1: Table S7

NA

 Odds ratio of vaccination effectiveness [40]

Matched: 0.35 (0.28–0.42)

Mismatched: 0.44 (0.34–0.57)

Beta

Proportion of side effects

 Proportion of fever [41]

0.00004274

Beta

 Proportion of injection site reaction [41]

0.00000854

Beta

 Proportion of anaphylaxis [41]

0.00000753

Beta

 Influenza vaccine coverage

Fully-funded policy: 0.400

Self-paid policy: 0.695

NA

Cost of illness and side effects

 Cost of self-medication [42]

High-risk children: 8.68 (6.944–10.416)

Low-risk children: 6.06 (4.848, 7.272)

Gamma

 Cost of outpatient [43]

 < 5 years: 197.96 (158.38–237.56)

5–14 years: 154.53 (123.63–185.44)

Gamma

 Cost of hospitalization [43]

 < 5 years: 1523.12 (1218.55–1827.83)

5–14 years: 1431.21 (1145.02–1717.53)

Gamma

 Cost of pneumonia [38]

1435.99 (1148.79–1723.19)

Gamma

 Cost of neurologic disorders [38]

5270.80 (4216.64–6324.96)

Gamma

 Cost of death [12]

 < 5 years: 15,230.12 (12,184.10–18,276.14)

5–14 years: 14,310.21 (11,448.17–17,172.25)

Gamma

 Discounted lifetime productivity [38]

Additional file 1: Table S9

NA

 Cost of fever [42]

High-risk children: 8.68 (6.944–10.416)

Low-risk children: 6.06 (4.848–7.272)

Gamma

 Cost of injection site reaction [24]

77.53 (0–863.66)

Gamma

 Cost of anaphylaxis [24]

1990.25 (65.76–17,388.08)

Gamma

Utilities

 Background health utility [46]

0.996 (0.953–1)

Beta

 Utility of outpatient [45]

 < 5 years: 0.6286 (0.5029–0.7543)

5–14 years: 0.6216 (0.4720–0.7080)

Beta

 Utility of hospitalization [45]

 < 5 years: 0.5900 (0.4973–0.7459)

5–14 years: 0.6132 (0.4906–0.7358)

Beta

 Self-medication (QALY loss)

0.005 (0.001–0.01)

NA

 Pneumonia (QALY loss) [24]

0.08 (0.054–0.1)

NA

 Neurologic disorders (QALY loss) [24]

0.08 (0.054–0.1)

NA

 Anaphylaxis (QALY loss) [24]

0.020 (0.006–0.041)

NA