Question

At present, the infection rate of COVID-19 in New York City is about 2.5%. A widely used nucleic acid based test has sensitivity of 93.8% and specificity 95.6%. Here, to quote Wikipedia: “sensitivity (also called the true positive rate, the recall, or probability of detection in some fields) measures the proportion of actual positives that are correctly identified as such; specificity (also called the true negative rate) measures the proportion of actual negatives that are correctly identified as such.” If a New Yorker (resident of NYC) received a positive test result, what is the probability that s/he actually has COVID-19?

Answer 1