Medmastery: PPV and Specificity
Franz Wiesbauer looks at the impact of specificity and sensitivity on positive predictive value (and thus validity of a test) and why one has a bigger impact than the other.
John Snow (1813-1858) was one of the first anaesthetists – he even chloroformed Queen Victoria! – but today he is famous for his investigation of the 1854 Broad Street cholera outbreak in Soho, London. By mapping the cases of cholera…