The $787 billion stimulus package signed by President Obama on Tuesday dedicates $1.1 billion for head-to-head research to determine which drugs, devices, and procedures are most effective and carry the lowest risk.

The money will be split between the National Institutes of Health, the Department of Health and Human Services, and the Agency for Healthcare Research and Quality.

The legislation also creates a board, called the Federal Coordinating Council for Comparative Clinical Effectiveness Research, to oversee and direct the studies, which will likely include literature reviews as well as independent trials.

A systematic review identifies an intervention for a specific disease or other problem in health care, and determines whether or not this intervention works. To do this authors locate, appraise and synthesize evidence from as many relevant scientific studies as possible. They summarize conclusions about effectiveness, and provide a unique collation of the known evidence on a given topic, so that others can easily review the primary studies for any intervention.

Systematic reviews differ from other types of review in that they adhere to a strict design in order to make them more comprehensive, thus minimizing the chance of bias, and ensuring their reliability. Rather than reflecting the views of the authors, or being based on a partial selection of the literature, (as is the case with many articles and reviews that are not explicitly systematic), they contain all known references to trials on a particular intervention and a comprehensive summary of the available evidence. The reviews are therefore also valuable sources of information for those receiving care, as well as for decision makers and researchers.