For Providers

Sentinel System's Story


FDA's Sentinel Initiative - Medical Product Surveillance

In 2007, Congress passed the FDA Amendments Act (FDAAA), requiring that FDA establish a system to monitor drugs using electronic healthcare data. The Sentinel System complements FDA’s existing monitoring capabilities, such as MedWatch, by using administrative and claims data to monitor the use of FDA regulated medical products and potential outcomes of treatment. The Sentinel System allows FDA to proactively assess products’ safety and, as a result, the FDA is better able to understand the risks of medical products.    




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Sentinel System's Current Capabilities

The Sentinel System’s data infrastructure involves a distributed data network that can ask questions of data held by participating health plans, insurers, and hospital networks.1 These organizations maintain physical and operational control over their respective electronic data in their existing environments. To facilitate analysis, they each transform a copy of their data into a common data model that contains standardized administrative and clinical information. 

Currently, the Sentinel System can analyze over 300 million person-years of high quality, unduplicated, curated data, working with a broad group of scientific collaborators who regularly provide technical support in evaluating this information for FDA review. When data from Sentinel System queries are evaluated and a potential problem is identified, FDA may require additional study, or initiate specific actions, such as revised labeling requirements, restricted use, issuance of a MedWatch alert, or even removal of a product from the market.


The Sentinel System Protects Patient Privacy

The Sentinel System aggregates data and produces summary information from large patient cohorts treated with the same drug or vaccine, whenever possible. When individual level data are needed, patients’ identifiers are removed. 


Sentinel System's Outcome Assessments

The Sentinel System has been used to ascertain valuable information about new prescription medications and vaccines. As an example, the bleeding rates of dabigatran and warfarin were compared.2 The Sentinel System’s preliminary analysis did not identify excess risk associated with dabigatran; a more detailed follow up study is nearing completion. In another instance, the Sentinel System found that the administration of a first dose of a rotavirus vaccine led to an increased risk of intussusception, which was not detected during clinical trials before FDA approved the new vaccine.3 A final illustration of the Sentinel System’s usefulness involved demonstrating that children vaccinated with a particular influenza vaccine were not at an increased risk of seizures.    


Sentinel System's Future

Although the FDA has focused much of its efforts thus far on the development of the Sentinel System for medical product safety assessment, the Sentinel System’s underlying infrastructure has the potential for much broader use. FDA will continue to explore the potential for the Sentinel System’s resources to support broad evidence generation to further promote drug safety, help ensure public health, and inform clinical decision making.4,5      



  1. Psaty BM, Larson EB. Investments in Infrastructure for Diverse Research Resources and the Health of the Public. JAMA. 2013;309(18):1895-1896.
  2. Pradaxa (dabigatran etexilate mesylate): Drug Safety Communication—Safety Review of Post-Market Reports of Serious Bleeding Events. US Food and Drug Administration website. Accessed September 29, 2016
  3. RotaTeq (Rotavirus Vaccine) and Intussusception Information. US Food and Drug Administration website. Accessed September 29, 2016
  4. Psaty BM, O’Donnell CJ, Gudnason V, et al; CHARGE Consortium. Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium: Design of prospective meta-analyses of genome-wide association studies from 5 cohorts. Circ Cardiovasc Genet. 2009;2(1):73-80
  5. Floyd JS, Psaty BM. Observational comparative effectiveness studies of drug therapies: high-quality answers or important clinical questions?: comment on “Comparative effectiveness of 2 β-blockers in hypertensive patients.” Arch Intern Med. 2012;172(18):1412-1414