Identifying Risk Factors for Infections: The Role of Meta-analyses

Systemic reviews and meta-analyses of risk factors for infections are assuming greater importance in influencing policy makers worldwide. Meta-analyses of risk factors for infections should strictly follow guidelines for meta-analysis of observational studies. A study protocol should be written in advance, completed literature searches should be performed, and studies selected in a reproducible and objective fashion. Biologic plausibility should be addressed. Reported findings should be interpreted with caution, taking into account the limitations of methodologic aspects of risk factors studies.