Fit of non-linear regression model describing the rapid diagnostic test’s positive predictive value depending on the score within the derivation cohort. Full circles labeled “observed” represent positive predictive value within intervals represented by median score. Interval limits were chosen to ensure equal number of positive results per interval.
Elias et al. BMC Infectious Diseases 2013 13:111 doi:10.1186/1471-2334-13-111