Table 2.

Initial Model Definitions and Formulas Used for Population Estimates

TermDefinition
HospCalculated number of hospitalized patients (including MEDSURG and ICU)
ICUCalculated number of patients requiring care in the intensive care unit (including Vent and no Vent)
VentCalculated number of patients in the ICU requiring mechanical ventilation
MedSurgCalculated number of patients requiring inpatient admission but not ICU care
MetroCalculated totals for the Greater New Orleans Metropolitan Area
DCCalculated number of patients discharged at the specified time point
Input VariableDefinition
R0Basic reproduction number (R0=3; R0=2; R0=1.5 assuming social distancing)
βContacts per unit time
γ1/mean recovery time = 1/(incubation + symptoms)
tTime, days
StTotal susceptible at time t
ItTotal infected at time t
New ItNewly infected at t
RtTotal recovered at time t
New RtNewly recovered at t
SXtCalculated symptomatic at time t
INCubtCalculated incubated at time t
Population EstimateFormula
Susceptible todayStoday = Syesterday – New Itoday
Infected todayItoday = Iyesterday + New Itoday – New Rtoday
Recovered todayRtoday = Ryesterday + New Rtoday
Symptomatic todaySXtoday = number infected 5 days prior to time today = It-5
Incubating todayINCubtoday = Itoday – SXtoday
Newly infected todayNew Itoday = (β * Iyesterday * Syesterday) / Sinitial
Newly recovered todayNew Rtoday = γ * Iyesterday
New Metro HospNumber newly infected 5 days prior * 0.09
New Metro ICUNumber newly infected 5 days prior * 0.032 – New Metro Vent
New Metro VentNumber newly infected 5 days prior * 0.023
New Metro Hosp_DCNumber hospitalized 7 days prior / 7
New Metro ICU_DCNumber patients in ICU – no Vent 11 days prior / 11
New Metro Vent_DCNumber patients in ICU 14 days prior / 14
Total Metro Cases todayTotal Metro Casesyesterday + New Metro Hosptoday + New Metro ICUtoday
Total Metro inpatients todayTotal Metro Hosptoday + Total Metro ICUtoday + Total Metro Venttoday
Total Metro Hosp todayTotal Metro Hospyesterday + New Metro Hosptoday – New Metro Hosp_DCtoday
Total Metro ICU todayTotal Metro ICUyesterday + New Metro ICUtoday + New Metro Venttoday – New Metro ICU_DCtoday – New Metro Vent_DCtoday
Total Metro Vent todayTotal Metro Ventyesterday + New Metro Venttoday – New Metro Vent_DCtoday
Market share = 45%MedSurgtoday = Total Hosptoday * 0.45 ICUtoday = Total ICUtoday * 0.45 Venttoday = Total Venttoday * 0.45