title: Assessment of the "case-chaos" design as an adjunct to the case-control design.
abstract: In 2012, a novel case series method dubbed the "case-chaos" design was proposed as an alternative to case-control studies, whereby controls are artificially created by permutating the exposure information of the cases. Our aim in the current work was to further evaluate the case-chaos method. Using a theoretical example of 2 risk factors, we demonstrated that the case-chaos design yields risk estimations for which the odds ratios obtained for every risk factor are in the same ascending order as the risk factors' exposure prevalences in the case group. Applying the method to data from the European Study of Severe Cutaneous Adverse Reactions (EuroSCAR; 1997-2001), we were not able to obtain sensible results but instead produced results as predicted by our theoretical assessment. We therefore claim that the method is equivalent to declaring risk solely on the basis of prevalences obtained in cases. While the proposers of the case-chaos method view it as a useful adjunct, we show that it cannot produce sensible estimates.
authors.forename: Sam
authors.initials: S
authors.lastname: Doerken
authors.forename: Maja
authors.initials: M
authors.lastname: Mockenhaupt
authors.forename: Martin
authors.initials: M
authors.lastname: Schumacher
authors.forename: Peggy
authors.initials: P
authors.lastname: Sekula
mesh_terms: D003198:Computer Simulation; D004812:Epidemiologic Methods; D006801:Humans; D016017:Odds Ratio; D012107:Research Design / Q000706:statistics & numerical data*; D018570:Risk Assessment; D012307:Risk Factors; D013262:Stevens-Johnson Syndrome / Q000453:epidemiology
keywords: Stevens-Johnson syndrome; case-control studies; research design; toxic epidermal necrolysis