Fig. 3

Estimated predictive values of typical CT findings and rapid antigen test (RAT). The black lines indicate predictive values and 95% confidence intervals for RAT, and the blue lines indicate predictive values and 95% confidence intervals for typical CT findings. Square indicates summary points of sensitivity and specificity, and solid black curvilinear line passing through summary point is the estimated summary ROC curve. Black dashed line and blue dashed line represent 95% confidence region and prediction region respectively. *Proportion of prediction region to area under ROC curve = 35.8%