The vast majority of previous CER consists of systematic reviews of published research studies. However, many of the studies included in the reviews are not considered CER; placebo-controlled trials far outnumber head-to-head trials, so comparisons between treatments are mainly indirect. Stakeholders increasingly demand that newly developed CER move beyond reviews, employing head-to-head comparisons of alternative treatments and enhancing internal validity through randomization of study subjects, while also increasing their generalizability to real-world settings by expanding the types of intervention strategies and inclusiveness of patient populations. The goal is to provide data that better guide a larger share of decisions about diagnosis and treatment.
The American Recovery and Reinvestment Act of 2009 (ARRA) provided more than
$1 billion in funding for CER, channeled through the National Institutes of Health (NIH), the Department of Health and Human Services (HHS), and the Agency for Healthcare Research and Quality (AHRQ). The Affordable Care Act established the Patient-Centered Outcomes Research Institute (PCORI), a private nonprofit entity, to oversee such research. Achieving widespread practice change in response to CER will require not only a large number of focused CER studies, but also timely dissemination and adoption of the results. Recognizing this fact, a sizable portion of the ARRA funding was devoted to research on the dissemination and implementation of CER.