Plain language summary:
Much work has discussed how studies that partner with multiple separate
databases can address things that create bias for estimates from
specific databases. Little attention has been paid, however, to how
these studies consider differences in characteristics between the
databases and specific groups of people treatment effects may be
relevant to (sometimes referred to as “external validity”). This work
describes various concepts related to external validity and how they
relate to these multi-database studies, discusses how Sentinel, CNODES,
and PCORnet (three such database partnerships) address these concepts,
and considers how each of their approaches reflects the structure and
purpose of that specific partnership.