BACKGROUND: Interpreting the findings of multi-data base studiesrequires a clear understanding of the context and purpose of data col-lection for each participating data source. There is currently no guid-ance for how heterogeneity between data sources (HDS) should bereported and leveraged upon. The DIVERSEscoping review on thistopic is sponsored by ISPE.
OBJECTIVES: To report on the selection for a scoping review to identifyliterature describing recommendations, or tools to describe, report onor leverage HDS for pharmacoepidemiologic research.
METHODS: We identified relevant literature published up to end 2021.We first selected a set of core papers, based on the expertise of theco-authors. We then executed three steps: 1) a snowball search of thereference lists of the core papers, 2) a PubMed search and 3) a web-based search for gray literature. Documents were reviewed in a stan-dardized process by independent pairs of reviewers; first title andabstract (TIAB), then full text review (FTR) if TIAB was of interest. Weexcluded documents if they met any of the following criteria: 1)described only clinical trials and not observational (or routinely col-lected) data sources, 2) reported only statistical methods to handleheterogeneity in results (e.g. meta-analysis), 3) applied pharmacoepi-demiologic studies that were not focussed on methodology or provid-ing guidance, 4) papers otherwise out of scope (e.g. pre-clinicalstudies). We included documents if they reported at least one of thefollowing: 1) relevant descriptions of multiple data sources, 2) tools toreport on HDS, 3) strategies to use HDS to improve evidence, 4) guid-ance on reporting HDS. The initial core papers were automaticallyincluded in the scoping review.
RESULTS: We selected 23 core documents and retrieved 687 docu-ments (total=710). After TIAB, 186 documents (27.1% of 687) were ncluded for FTR. After FTR, 50 (26.9% of 186) were included in thescoping review by the independent pair of assessors. Including thecore papers, a total of 73 documents entered the scoping review,42 (57.5%) included relevant descriptions of multiple data sources,42 (57.5%) included tools to report on HDS, 52 (71.2%) included strat-egies to use HDS to improve evidence, and 32 (43.8%) included guid-ance on reporting on HDS.
CONCLUSIONS: Among the reviewed papers, a minority included guid-ance on reporting diversity,while a higher number included descriptions, tools, and strategies.This set of papers will undergo further content analysis, to extractcommon themes and identify knowledge gaps. This scoping reviewwill eventually inform the development of a guidance paper.
