Real-World Evidence

Early discussions about comparative effectiveness research (CER) in the United States focused on defining “comparative” and determining the implications for research. Health care stakeholders were talking about the broad array of what should be compared, such as drugs, surgery, devices, physical therapy, primary care doctors versus specialists, how care is delivered, and what the relevant comparisons are among the varied technologies and services. Today, the focus has shifted from looking simply at what should be compared to how comparative studies should be designed to answer the practical questions about “effectiveness,” particularly in real world settings. The question now becomes does a treatment, service, or method of delivering care work when applied in real world, clinical practice environments?

To answer that question, health care stakeholders need to think beyond traditional randomized controlled trials (RCTs). One way to consider is to make use of real-world databases that record the processes of care patients receive, such as electronic medical record (EMR) and medical claims databases. We also might work with patient registries that focus on patients with a specific disease or who receive a particular treatment or device and record the medical outcome for those patients; or these registries could be based on a specific population so that researchers can see what happens within that population.

Because more of these public databases are becoming available, we need to ensure that there are sound ways to use the information to address effectiveness questions. Analyses of these data are already underway, and as results become available, we will have to pay better attention to them and any limitations inherent in those results. For example, studies that use these data cannot randomize patients to treatments or services to be studied, and thus the bias of confounding, and other potential biases, need to be considered so that differences observed in results are due to the treatments used and not other factors that were not a part of or controlled for in the study.

Another way of looking at the real world is via practical clinical trials that relax some of the constraints of a normal trial and better reflect the real world conditions of clinical practice. Participants in routine RCTs usually must meet very precise clinical criteria, and thus the information gained from the trial may not be “generalized” to a broader group of patients. Typical RCTs also define the frequency of visits and tests to be performed, and compliance with treatments is closely monitored and controlled. These characteristics are not typical of usual care patients receive and thus the real benefits over usual care are more difficult to assess. In practical trials, patients may be randomized to treatments under study, but subsequent care may be determined by the doctor based on his or her clinical judgment. Practical trials often include a comparison group receiving usual care rather than a placebo comparison.