Выражение встречается в следующем контексте:
Association between drugs and allergic adverse reactions was assessed using the case/non-case method, calculating the ADR reporting odds ratio (ROR) as a measure of disproportionality.

Заранее спасибо

In 1997, the study by Moore et al., [31] introduced the concept of “case/non case method” when performing pharmacovigilance analyses. They postulated that this term was a more effective representation than case-control: controls are not actual controls since they are all exposed to at least one drug, and have at least one event (there are no untreated `healthy' controls)