The US Food and Drug Administration’s (FDA) Mini-Sentinel Program is an important initiative to identify adverse effects of new medications during the postapproval period. The system links electronic data from a variety of health care providers so as to rapidly determine the safety of medications in use.
The system is especially useful for identifying adverse effects that might not be apparent in randomized clinical trials because they are rare, occur in patient groups not included in the trials, occur when used in settings less controlled than randomized trials, or occur in patients taking the medications for periods of time longer than the length of the trial. Nonetheless, it must be remembered that analysis of the data in this surveillance system, however rich, may suffer from the limitations of any observational study.
Sipahi et al used a systematic search and meta-analysis of randomized clinical trials to estimate the rate of gastrointestinal tract bleeding with dabigatran vs warfarin. Their data support a very different conclusion than that of the FDA Mini-Sentinel Program. While the Mini-Sentinel Program found that gastrointestinal tract bleeding rates were no higher with dabigatran than warfarin, the randomized clinical data showed a significantly increased risk of gastrointestinal tract bleeding compared with warfarin.
It is not surprising, or uncommon, for different methodologies to reveal different answers. Using electronic data from health care settings is a smart and efficient method of learning more about medications in real-world settings. However, new data, especially from observational studies, which are prone to confounding and underreporting, must always be judged in the context of biologic plausibility and other data sources.
Katz MH. Multiple Data Sources, the Best Way to Gather Safety Information About Medications. JAMA Intern Med. 2014;174(1):151. doi:10.1001/jamainternmed.2013.11488