A test of statistical significance. A Chi Square (X2) test looks at the difference between what we observe in the data and what we would expect if the exposure was not associated with the illness
Cornell University, Department Neurobiology and Behavior, Course: Clinical Neurobiology, Glossary of Epidemiological Terms, New York, USA 2012. https://courses.cit.cornell.edu/bionb4280/Epidemio logy%20Terms.pdf, (Dzstr Prep/ Epid - Amer) {1004}