Figure 1.  Diagram of two approaches to estimating the symptomatic case-fatality ratio (sCFR), shown in black.  Approach 1 used three data sets to estimate successive steps of the severity pyramid.  Approach 2 used self-reported influenza-like illness for the denominator, and confirmed deaths for the numerator, both from New York City.  Both approaches used prior distributions, in some cases informed by additional data, to inform the probability of detecting (confirming and reporting) cases at each level of severity (not shown in the diagram; see Appendix).  The Bayesian evidence synthesis framework was used as a formal way to combine information and uncertainty about each level of severity into a single estimate and associated uncertainty that reflected all of the uncertainty in the inputs.