Michael L. Nance, MD, serves as chief of the Division of Pediatric General, Thoracic, and Fetal Surgery and director of the Pediatric Trauma Program at the Children’s Hospital of Philadelphia (CHOP). He is also associated with CHOP’s Center for Violence Prevention.
Nance has authored numerous articles on gun violence and its impact on children. One such article from 2020 stated: “Firearms are the second leading cause of trauma-related death in children in our Trauma Centers,” Nance said in a news release. “Our findings highlight the sheer extent of the problem and show how closely mass shootings are tied to our communities, and especially to the places where children learn and play.”
A key point raised concerns how Nance’s team defines mass shootings. The FBI defines a mass shooting as an event where four or more people are murdered. However, Nance’s research uses a broader definition: “The researchers defined mass shootings as events involving four or more people injured or killed by a firearm in a single setting, using data from the 2019 Gun Violence Archive,” according to his article.
The Gun Violence Archive (GVA) was established in 2013 by Michael Klein and Mark Bryant. GVA’s definition results in significantly higher reported numbers; for example, it counted 417 mass shootings in 2019 compared to 30 reported by the FBI that year. The Biden administration and various media outlets have used GVA data when discussing mass shootings.
Mark Bryant has explained that GVA researchers use about 7,500 sources including law enforcement social media accounts, police blotters, and media reports. He acknowledged inconsistencies in media reporting after incidents but noted that these issues did not affect their main audience so long as high numbers were maintained.
Nance has repeatedly cited GVA data across multiple studies published between 2020 and earlier years. In one case from March 2020, his team claimed: “Most Mass Shootings Occur Closest to Hospitals without Verification to Treat Trauma.” Another study analyzed locations relative to schools using GVA records for calendar year 2019.
Earlier work by Nance did not rely on GVA data but instead examined access to gun dealers across U.S. cities. His conclusions suggested regulatory changes could reduce gun homicides.
Nance declined requests for comment regarding his use of data sources.
As an author responsible for his publications’ content and accuracy, questions remain about reliance on varying definitions and datasets within academic work focused on firearms injuries among youth populations.
