Reporting, handling, and judging risk of bias associated with missing participant data in systematic reviews

Poster
2012 Auckland
Akl E1, Alonso-Coello P2, Neumann I3, Brignardello-Petersen R3, Carrasco-Labra A3, Johnston B4, Glujovsky D5, Iorio A3, Irfan A6, Martinez L2, Mustafa R3, Ramirez-Morera A7, Solá I2, Sultan S8, Tikkinen K9, Vandvik P10, Zhang M3, Guyatt G3
1Department ofMedicine, State University of New York, US
2Iberoamerican Cochrane Centre. Institute of Biomedical Research (IIB Sant Pau) Barcelona, Spain
3Department of Clinical Epidemiology & Biostatistics, McMaster University, Canada
4Research Institute, Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, Canada
5Argentine Cochrane Centre IECS (Institute for Clinical Effectiveness and Health Policy), Buenos Aires, Argentina
6Internal Medicine Residency Program, University of Illinois at Urbana-Champaign
7CCSS Permanent Medical Advisor, Health Care Development Division. IHCAI FOUNDATION & Central America Cochrane branch associated fellow, Costa Rica
8Division of Gastroenterology, Hepatology, and Nutrition, Malcom Randall Veterans Affairs Medical Center, University of Florida College of Medicine
9Dept. of Urology, Helsinki University Central Hospital, Helsinki, Finland
10Norwegian Knowledge Centre for the Health Services, Oslo, Norway

Background:

Systematic reviewer authors need to consider study participants with missing data, and how that missing data impacts on risk of bias.

Objectives:

To describe methods being used in systematic reviews for reporting, handling, and judging risk of bias associated with missing participant data.

Methods:

We searched Medline and the Cochrane Database of Systematic Reviews for systematic reviews of randomized controlled trials published in 2010 and reporting a meta-analysis of a dichotomous outcome. After teams of two reviewers screened studies for eligibility, we randomly selected 75 Cochrane and 75 non-Cochrane reviews. Teams of two reviewers are currently abstracting data using standardized, piloted forms and written instructions. We are abstracting from the methods section of systematic reviews whether the reviewers reported: their plan to collect information about missing participant data, how they will handle them, and the criteria and tools for assessing their impact on risk of bias. We will abstract from the results section whether and in what format the reviewers reported missing participant data. We will document the extent to which the authors discuss the implications of missing participant data.

Results:

Data abstraction is ongoing. The results of analyses will be available for presentation at the colloquium.

Conclusions:

The results of this study will provide insight on how systematic review authors are addressing missing participant data. Our findings will inform the development of specific guidance for Cochrane review authors on optimal ways of addressing missing participant data.