Table 2 List of information environment indices used in pandemic and non-pandemic model

$k_{1,\theta ,t}^p$

β _j,t,2

Sea.flu

Google search index for seasonal flu terms

$k_{2,\theta ,t}^p$

β _j,t,3

Symp

Google search index for symptoms

$k_{3,\theta ,t}^p$

β _j,t,4

Med

Google search index for medications

$k_{4,\theta ,t}^p$

β _j,t,5

Non-flu

Google search index for non-flu terms

$k_{1,\phi ,t}^p$

α _j,t,2

Total

HealthMap total number of alerts

$k_{2,\phi ,t}^p$

α _j,t,3

Unique

HealthMap number of unique alerts

$k_{3,\phi ,t}^p$

α _j,t,4

HCF

HealthMap number of healthcare facilities related alerts

$k_{4,\phi ,t}^p$

α _j,t,5

%RSV

Lab surveillance% RSV tested positive

$k_{5,\phi ,t}^p$

α _j,t,6

Authority

Google search index for authority

$k_{6,\phi ,t}^p$

α _j,t,7

Pan.flu

Google search index for pandemic flu terms

$k_{1,t}^{\mathit{np}}$

ρ _s,j,t,2

Non-flu Index

Avian influenza, bird flu, common cold, severe acute respiratory syndrome (SARS), pneumococcus,% RSV

$k_{2,t}^{\mathit{np}}$

ρ _s,j,t,3

Illness Index

body temp,% RSV, cough, fever, nasal congestion, cough relief remedies, headache, common cold, pediatric, paediatric

$k_{3,t}^{\mathit{np}}$

ρ _s,j,t,4

Public-awareness Index

CHP, Hospital Authority, Ministry of Health, disinfect, flu, influenza, pandemic, epidemic, school closures, total number of HealthMap alerts, number of healthcare facilities related alerts, number of school related alerts, number of “breaking” alerts