(1) Determination of Outcome Areas
We used an updated and most comprehensive taxonomy of outcomes developed for use in medical research, encouraging consistency across clinical trials to promote more effective categorization, reporting, and searching of outcomes in the literature.3 Having undergone numerous iterations to account for advancements within the field, the system evolved from a 12-category system, to now include 38 categories, representing as many outcomes as can possibly be reported in health-related studies.3, 17 These outcomes are grouped under five core areas – (1) mortality/survival outcomes; (2) system-specific morbidity (physiological/clinical) outcomes; (3) functioning or life-impact outcomes; (4) resource-use outcomes and (5) adverse events/effects.3 This taxonomy was employed as the foundation of the COR Tool, with minor modifications. For example, we separated the outcome domain ‘delivery of care’ from within the outcome areas ‘functioning/ life-impact’, as it was deemed to be a distinct entity, encompassing its own unique sub-divisions. We therefore identified six distinct outcome areas for the COR tool. Further, because obstetrics involves two individuals – mother and fetus, each of these six distinct outcome areas are considered individually for both, leading to a total of twelve outcome categories.