RESEARCH ARTICLE
Reporting of Adverse Events in Published and Unpublished Studies of Health Care
Interventions: A Systematic Review
Su Golder1*, Yoon K. Loke2, Kath Wright3, Gill Norman4
1Department of Health Sciences, University of York, York, United Kingdom,2Norwich Medical School,
University of East Anglia, Norwich, United Kingdom,3Centre for Reviews and Dissemination (CRD),
University of York, York, United Kingdom,4School of Nursing, Midwifery & Social Work, University of
Manchester, Manchester, United Kingdom
Conclusions
There is strong evidence that much of the information on adverse events remains unpub-
lished and that the number and range of adverse events is higher in unpublished than in
published versions of the same study. The inclusion of unpublished data can also reduce
the imprecision of pooled effect estimates during meta-analysis of adverse events.