Multiplier to estimate attended mild/moderate flu cases

The Flu Tool applies a multiplier to extrapolate from hospitalized cases in order to generate an estimate for the number of ICU-level flu hospitalizations. Default values are pre-filled below. You may use the default values or edit, as needed, to reflect your hospitalization estimates. If you choose to enter a custom multiplier, you must also enter confidence intervals.



	Lower CI
	Upper CI

	Lower CI
	Upper CI

	Lower CI
	Upper CI

	Lower CI
	Upper CI

	Lower CI
	Upper CI

More about the default multipliers

The default multipliers have been calculated based on a systematic review of the peer-reviewed literature. Multipliers are applied to the number of flu-related hospitalizations to generate estimates of flu cases at other levels of disease severity (e.g., deaths, ICU-level hospitalizations, mild/moderate cases) and accompanying confidence intervals. Additional detail about the methodology is available here.

How would I calculate my own multipliers?

Multipliers are estimates based on analysis of data for flu-related hospitalizations and at least one other level of disease severity (e.g., deaths, ICU-level hospitalizations, mild/moderate cases). If you have reliable data, it is possible to generate your own multiplier by determining the ratio between the number of flu-related hospitalizations and number of cases for the other disease severity level. Additional information is available here (Methods section). The strength of the default multipliers is that they are calculated based on multiple studies from around the world; however, generating custom multipliers using data specific to your country or region could provide more accurate estimates.