Susan L Norris1, David Moher2, Barnaby C Reeves3, Beverley Shea4, Yoon Loke5, Sarah Garner6, Laurie Anderson7, Peter Tugwell8, George Wells8. 1. Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, OR, USA. 2. Ottawa Hospital Research Institute, Ottawa, ON, Canada. 3. Bristol Heart Institute, Bristol Royal Infirmary, University of Bristol, Bristol, UK. 4. Community Information and Epidemiological Technologies, Institute of Population Health, Ottawa, ON, Canada. 5. Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK. 6. National Institute for Health and Clinical Excellence, London, UK. 7. School of Public Health, University of Washington, Seattle, WA, USA. 8. Centre for Global Health, Institute of Population Health, Ottawa, ON, Canada.
Abstract
BACKGROUND: Selective outcome and analysis reporting (SOR and SAR) occur when only a subset of outcomes measured and analyzed in a study is fully reported, and are an important source of potential bias. KEY METHODOLOGICAL ISSUES: We describe what is known about the prevalence and effects of SOR and SAR in both randomized controlled trials (RCTs) and non-randomized studies (NRS), and the effects of SOR and SAR on summary effect estimates and conclusions in systematic reviews of the effectiveness of healthcare interventions. GUIDANCE: Review authors should always suspect SOR and SAR in reviews that include NRS, assess primary studies for the risk of bias, and make reasonable attempts to retrieve study protocols or other documentation developed before study recruitment began. There are clues that may suggest SOR or SAR in NRS, including differences between the methods and results sections of the publication, study funder, and differences between study protocol or registration information and the study report. CONCLUSION: Existing evidence about reporting biases in primary studies comes almost exclusively from methodological reviews of RCTs. The prevalence and impact of SOR and SAR in NRS are likely even greater than in RCTs but it is difficult to identify and confirm selective reporting in NRS.
BACKGROUND: Selective outcome and analysis reporting (SOR and SAR) occur when only a subset of outcomes measured and analyzed in a study is fully reported, and are an important source of potential bias. KEY METHODOLOGICAL ISSUES: We describe what is known about the prevalence and effects of SOR and SAR in both randomized controlled trials (RCTs) and non-randomized studies (NRS), and the effects of SOR and SAR on summary effect estimates and conclusions in systematic reviews of the effectiveness of healthcare interventions. GUIDANCE: Review authors should always suspect SOR and SAR in reviews that include NRS, assess primary studies for the risk of bias, and make reasonable attempts to retrieve study protocols or other documentation developed before study recruitment began. There are clues that may suggest SOR or SAR in NRS, including differences between the methods and results sections of the publication, study funder, and differences between study protocol or registration information and the study report. CONCLUSION: Existing evidence about reporting biases in primary studies comes almost exclusively from methodological reviews of RCTs. The prevalence and impact of SOR and SAR in NRS are likely even greater than in RCTs but it is difficult to identify and confirm selective reporting in NRS.
Authors: Zhongheng Zhang; Yucai Hong; Nathan J Smischney; Han-Pin Kuo; Panagiotis Tsirigotis; Jordi Rello; Win Sen Kuan; Christian Jung; Chiara Robba; Fabio Silvio Taccone; Marc Leone; Herbert Spapen; David Grimaldi; Sven Van Poucke; Steven Q Simpson; Patrick M Honore; Stefan Hofer; Pietro Caironi Journal: J Thorac Dis Date: 2017-02 Impact factor: 2.895
Authors: Penny A Dacks; Sandrine Andrieu; Deborah Blacker; Aaron J Carman; Allan M Green; Francine Grodstein; Victor W Henderson; Bryan D James; Rachel F Lane; Joseph Lau; Pei-Jung Lin; Barnaby C Reeves; Raj C Shah; Bruno Vellas; Kristine Yaffe; Karin Yurko-Mauro; Diana W Shineman; David A Bennett; Howard M Fillit Journal: J Prev Alzheimers Dis Date: 2014-02
Authors: Bruna S Mota; Rachel Riera; Marcos Desidério Ricci; Jessica Barrett; Tiago B de Castria; Álvaro N Atallah; Jose Luiz B Bevilacqua Journal: Cochrane Database Syst Rev Date: 2016-11-29