Integrating Causal Inference, Evidence Synthesis, and Research Prioritization Methods [Methods Study], United States, 2013-2018

Comparative effectiveness research compares two or more treatments to see which one works better for certain patients. For example, research can see if medicines or stents work better for people with heart problems. Such research may include:

Observational studies. A research team studies what happens when patients and their clinicians choose the treatments. Traits, such as age or health, may affect patients' treatment choices. These traits may also affect patients' responses to treatments. It may be hard for the team to tell if a patient's traits, the treatment, or a mix of the two affected how well the treatment worked.
Clinical trials. The team assigns patients to a treatment by chance. Traits may affect a patient's ability to join a clinical trial.

In this study, the team tested ways to improve understanding of which treatment works better. First, the team compared different methods that account for things, such as patients' traits, that could affect results of observational studies. In the second part of the study, the team worked on ways to use all available data with a method called meta-analysis. This method combines data from both study types.