Table 1.

Arguments for and against including conference abstracts in systematic reviews

For	Against
Comprehensiveness increased	Resources may be inadequate for locating relevant conference abstracts
Potential for impact of publication bias decreased	Abstracts may not contain adequate information for systematic reviewers to appraise the design, methods, risk of bias, outcomes, and results of studies reported in the abstracts
Increased information leads to increased precision	Dependability of results presented in abstracts is questionable