Introduction: Systematic reviews are important tools to guide health care decisions. Reviewers can introduce bias at almost any stage in the development of a systematic review. It is important that strategies be developed to minimise or abolish these biases. In this abstract, we describe how we manipulated the type, timing and amount of input from reviewers with different expertise to reduce bias during a systematic review. We used early discharge of mothers and newborns after uncomplicated vaginal delivery as the example.

Methods: 4 reviewers were assembled and charged with conducting a systematic review of comparative studies on early discharge of mothers and new-borns after uncomplicated vaginal delivery. Aware of the potential for bias in the reviewing process, the team was assembled to include a consumer with little methodological and content expertise (a female medical student, mother of two), a clinician methodologist with little content expertise, a non-clinician with content expertise and a clinician methodologist with content expertise. The research question, and the inclusion and exclusion criteria were developed by all 4 reviewers. The literature search strategy, data extraction, assessment of strength of the evidence and the initial data synthesis were conducted by the two reviewers with no content expertise. The content experts provided comments on the drafts of the review, helped with additional data extraction and analysis, and provided insight to the meaning and significance of the findings. The reviewers believed this method contributed to enhancing the validity of the review. This strategy could contribute to reducing bias in systematic reviews in controversial areas where different groups of the population have vested interests and conflicting views. Empirical methodological studies are required to establish its value.