Reverse chronology quota record screening for realist synthesis: Fostering causally rich extrapolations with a diverse and contemporaneous sample of literature

Abstract Identifying studies for inclusion in realist syntheses using title and abstract screening is challenging given the need to unearth explanatory insights to build context–mechanism–outcome configurations. Such insights may only be uncovered through full-text paper reading. To address this issue, a novel approach for identifying studies has been developed called Reverse Chronology Quota Record Screening (RCQRS). Results of database searches are screened in reverse chronology, and in stages, to fill quotas matching the requirements of the review. RCQRS may be beneficial in any of the following circumstances: (a) the timeframe to complete the synthesis is short; (b) the scope of inquiry is not fully defined, (c) the availability of suitable literature is beyond the screening capacity of the reviewers; or (d) the availability of literature is sparse and reviewers seek to extrapolate insights from other areas. In contrast to RCQRS, exhaustive title and abstract screening (i.e., screening entire database results) may hamper study selection due to being overwhelming in volume and time-intensive, resulting in a causally thin cohort of papers for analysis. RCQRS used in stages, and in conjunction with other search strategies (e.g., hand searching, backward citation tracking, and expert solicitation) can support creative, robust analytical insights with causally rich extrapolations. Using the Horizon-EU funded SERENITY study on deprescribing in palliative care as a case example, the benefits and limitations of RCQRS are explored. Finally, a checklist template is offered for teams who wish to reflect on, and transparently report, the use of RCQRS in their realist synthesis.