Fig. 5From: Timeliness of contact tracing among flight passengers during the COVID-19 epidemic in VietnamCumulative hazard of successful tracing for passengers by method of index case detection (a) and nationality of passengers (b). * Cumulative hazards were estimated using Kaplan Meier and interpreted as probability of successful trace. p-value was calculated from log-rank tests. Note: Dotted lines indicated the 95% confidence intervalsBack to article page