Table 1.

Input Parameters Used to Calculate the Number of Patients With ILI Interacting With Healthcare Personnel in Different Settings and Usage by Scenario

Input	Lower Bound	Upper Bound	Source
Low severity scenario
% cases, hospitalized	0.8	1.5	[9]
% cases, visit EDa	6	12	[10]
% cases, transported by EMSb	1	2	[11]
High severity scenario
% cases, hospitalized	3	5	[9]
% cases, visit EDa	24	39	[10]
% cases, transported by EMSb	2	4	[11]
All scenarios
Pandemic case to ILI case multiplierc	1.39	1.70	[12]
% cases, seek outpatient care	40	56	[13]
% of hospitalizations requiring ICU	20	26	[14–16]
Length of stay (days)
ED	1
ICU	8	10	Adapted from [17]
General ward	7	11	Adapted from [17]
Workforce
Police officers in US (millions)d/% with public contact	0.45/90	0.58/90	[18, 19]
Firefighters in US (millions)e/% with public contact	0.34/90	1.10/90	[19, 20]
Hospital Workersf/% with patient contact	6 053 103/33		[19, 21]
Outpatient healthcare workersg/% with patient contact	3 205 399/67		[19, 21]
ED workers/% with patient contact	131 588/100		[22, 23] (as)
EMS workersh/% with patient contact	296 937/90		[21] (as)
Nursing home workersi/% with patient contact	3 426 571/25		[19, 21]
Demographics
United States population (millions)	316		[24]
% United States population 65+, in nursing homes	4		[25, 26]

Abbreviations: (as), assumed; ED, emergency department; EMS, emergency medical service; ICU, intensive care unit; ILI, influenza-like illness.

^a The number of ED visits was considered to be 7.8 greater than the number of Hospital Visits.

^b Approximately 12% of ED patients were transported by EMS.

^c At peak, 72% of specimens tested positive for influenza. 20% reduction assumed for upper bound of multiplier. For the sensitivity analysis, we considered a time varying pandemic case to ILI multiplier between 5.00 (in the beginning and end of the pandemic most cases are ILI, values adapted from [12, 17]), and 1.39 at peak.

^d Police officers: lower bound = # of sworn officers; higher bound = # of sworn officers and civilian police officers.

^e Firefighters: lower bound = # of professional firefighters; higher bound = # of professional firefighters and volunteer firefighters.

^f Includes workers in NAICS 622 (Hospitals). Includes Federal, State, Local, and Private Institutions, for 2013. (NAICS: North American Industry Classification System).

^g Includes workers in NAICS 6211 (Office of Physicians) and NAICS 6214 (Outpatient care centers). Includes Federal, State, Local, and Private Institutions, for 2013.

^h Includes workers in NAICS 621 493 (Freestanding emergency medical centers) and NAICS 62 191 (Ambulance Services). Includes Federal, State, Local, and Private Institutions, for 2013.

ⁱ Includes workers in NAICS 623 (Nursing and residential care facilities). Includes Federal, State, Local, and Private Institutions, for 2013.