Figure 2: Schematic illustration of the relationship between the observed data (rectangles) and the conditional probabilities (blue circles). The key quantities of interest, sCHR, sCIR, and sCFR are products of the relevant conditional probabilities.  (a) Approach 1, synthesizing data from New York City and Milwaukee.   Note that   (double circle) is informed by prior information [19]rather than observed data.  (b) Approach 2, using data from New York City only, including the telephone survey.  Abbreviations: sCFR: symptomatic case-fatality ratio; sCIR: symptomatic case-ICU (or mechanical ventilation) ratio; sCHR: symptomatic case-hospitalization ratio.  Variables: : the ratio of deaths to medically-attended cases; : the ratio of deaths to hospitalized cases; : the ratio of cases admitted to intensive care or using mechanical ventilation to hospitalized cases;  : the ratio of hospitalized cases to medically attended cases;  : the ratio of medically-attended cases to symptomatic cases; : the ratio of deaths to symptomatic cases;  : the ratio of hospitalized cases to symptomatic cases.