Fig. 3From: A methodological framework for the evaluation of syndromic surveillance systems: a case study of EnglandMedian T D per level of access to healthcare. Median T D for influenza outbreaks across four syndromic indicators for three different levels of access to healthcare (see Table 2). The dots indicate the median T D , and the error bars depict the 95% studentized bootstrap prediction intervals. Prediction intervals were estimated using 1000 bootstrap samples. Estimates with a probability of detection ≤75% were excludedBack to article page