Much of biomedical research is observational. The reporting of such research is often
inadequate, which hampers the assessment of its strengths and weaknesses and of a
study's generalizability. The Strengthening the Reporting of Observational Studies
in Epidemiology (STROBE) Initiative developed recommendations on what should be included
in an accurate and complete report of an observational study. We defined the scope
of the recommendations to cover three main study designs: cohort, case-control, and
cross-sectional studies. We convened a 2-day workshop in September 2004, with methodologists,
researchers, and journal editors to draft a checklist of items. This list was subsequently
revised during several meetings of the coordinating group and in e-mail discussions
with the larger group of STROBE contributors, taking into account empirical evidence
and methodological considerations. The workshop and the subsequent iterative process
of consultation and revision resulted in a checklist of 22 items (the STROBE Statement)
that relate to the title, abstract, introduction, methods, results, and discussion
sections of articles. Eighteen items are common to all three study designs and four
are specific for cohort, case-control, or cross-sectional studies. A detailed Explanation
and Elaboration document is published separately and is freely available on the web
sites of PLoS Medicine, Annals of Internal Medicine, and Epidemiology. We hope that
the STROBE Statement will contribute to improving the quality of reporting of observational
studies.