Session cochair Jeanne E. Poole, MD, professor of medicine and director of the clinical cardiac electrophysiology program at the University of Washington, Seattle, commented, “The problem, of course, with using these large databases is that you may not be able to find out important information, such as whether rivaroxaban was being taken appropriately with meals, which is frequently not the case. If it wasn’t, that decreases absorption and efficacy by 40%. That’s a limitation.”
Audience member James A. Reiffel, MD, rose to add that, in his view, another significant limitation of all real-world, observational analyses using claims data is that it’s not possible to know why physicians selected a given drug for a given patient. He used as an example a patient with atrial fibrillation and gastroesophageal reflux disease (GERD).
“People with GERD may be less likely to get dabigatran, and if they’re less likely to get dabigatran with GERD, maybe they’re less likely to get a GI bleed. I don’t know,” said Dr. Reiffel, professor of clinical medicine and director of the electrocardiography laboratory at Columbia University Medical Center, New York.
“We have to take all the real-world analyses with a little grain of salt,” he added.
Dr. Deitelzweig replied, “This study is not meant to be the be-all and end-all.”