Much medical research is observational. The reporting of observational studies is
often of insufficient quality. Poor reporting hampers the assessment of the strengths
and weaknesses of a study and the generalizability of its results. Taking into account
empirical evidence and theoretical considerations, a group of methodologists, researchers,
and editors developed the Strengthening the Reporting of Observational Studies in
Epidemiology (STROBE) recommendations to improve the quality of reporting of observational
studies. The STROBE Statement consists of a checklist of 22 items, which relate to
the title, abstract, introduction, methods, results, and discussion sections of articles.
Eighteen items are common to cohort studies, case-control studies, and cross-sectional
studies, and 4 are specific to each of the 3 study designs. The STROBE Statement provides
guidance to authors about how to improve the reporting of observational studies and
facilitates critical appraisal and interpretation of studies by reviewers, journal
editors, and readers. This explanatory and elaboration document is intended to enhance
the use, understanding, and dissemination of the STROBE Statement. The meaning and
rationale for each checklist item are presented. For each item, 1 or several published
examples and, where possible, references to relevant empirical studies and methodological
literature are provided. Examples of useful flow diagrams are also included. The STROBE
Statement, this document, and the associated Web site (www.strobe-statement.org) should
be helpful resources to improve reporting of observational research.