0 the number of all tests for an illness that are positive (= show that someone has the illness), expressed as a number out of a hundred:
These numbers probably underestimate the true positivity rate.
Quick testing has been successful in identifying people who were HIV positive, with as much as a 3% positivity rate.
Chan et al. reported a high positivity rate of 52.1 % in patients investigated during the SARS epidemic.
Seroprevalence studies have shown a positivity rate of the order of 30% in North America and Europe.
Other investigators either failed to detect viral DNA, or reported low positivity rates.
