Fig. 1: Proportion of cases with fever for the index cases and secondary cases for COVID-19, and their corresponding risk ratio of index cases, compared with secondary cases.
From: Using secondary cases to characterize the severity of an emerging or re-emerging infection

Red circles and lines indicate the proportion of fever of index cases and the corresponding 95% exact binomial confidence intervals. Blue triangles and lines indicate the proportion of fever of secondary cases and the corresponding 95% confidence intervals. Black squares and lines indicate the risk ratio of proportion of fever of index cases compared with secondary cases and the corresponding 95% confidence intervals calculated based on normal approximation. All statistical tests are two-sided tests. Adjustments are not made for multiple comparisons.