Table 1 List of parameters and other notation

X

Health status

0 - frail

1 - healthy

V

Vaccination status

0 - unvaccinated

1 - vaccinated

Y

ARI and influenza infection status

0 - no ARI

1 - NFARI

2 - FARI

M

Seeking medical care for ARI

0 - no

1 - yes

T

Result of test for influenza infection

0 - negative

1 - positive

C _A

Case/control status in TND study

0 - control

1 - case

C _B

Case/control status in TCC study

0 - control

1 - case

B

Participating in TCC study

0 - no

1 - yes

π

Probability of having better health status (i.e. healthy persons)

0.7

α _x

Probability of being vaccinated for a person of health status x

β _vx

Probability of NFARI for a person of vaccination status v and health status x

\(\rho _{\beta } = {{\beta _{1x}}\over {\beta _{0x}}}\)

Ratio comparing vaccinees and non-vaccinees w.r.t. probability of NFARI

0.5-2.0

\(\eta _{\beta } = {{\beta _{v1}}\over {\beta _{vo}}}\)

Ratio comparing healthy and frail persons w.r.t. probability of NFARI

0.5-1.0

γ _vx

Probability of FARI for a person of vaccination status v and health status x

\(\rho _{\gamma } = {{\gamma _{1x}}\over {\gamma _{0x}}}\)

Ratio comparing vaccinees and non-vaccinees w.r.t. probability of FARI

0.4^a

\(\eta _{\gamma } = {{\gamma _{v1}}\over {\gamma _{v0}}}\)

Ratio comparing healthy and frail persons w.r.t. probability of FARI

0.5-1.0

δ _SN

Probability of seeking medical care for ARI for an unvaccinated frail person with NFARI

δ _SF

Probability of seeking medical care for ARI for an unvaccinated frail person with FARI

λ

multiplier for the probability of seeking medical care for FARI or NFARI for a healthy person

0.5-2.0

Ψ _F

multiplier for the probability of seeking medical care for FARI for a vaccinated person

0.5-1.0

τ _e

Probability that a person of illness/infection status e tests positive for influenza infection

τ ₁=0, τ ₂=1