Football epidemiology

In an attempt to prove Cowen's First Law -- "there is literature on everything" -- I enjoy highlighting unusual epidemiological studies (see tornado epidemiology, for one.) These studies may seem a bit odd until you start thinking like an epidemiologist: measurement is the first step to control. The latest issue of Pediatrics has a new study by Thomas et al. on the "Epidemiology of Sudden Death in Young, Competitive Athletes Due to Blunt Trauma." Some of the methods seem a bit sketchy, but that's kind of the authors' point as they note,

"without a systematic and mandatory reporting system for sudden cardiac deaths in young competitive athletes, the true absolute number of these events that occur in the United States cannot be known."

While this study is mostly concerned with the sudden deaths not caused by cardiac events, the same principle holds true: if anything, the problem is under-reported.

Thomas et al. use 30 years of data from the "US National Registry of Sudden Death in Young Athletes," looking at 1980–2009. Deaths in the database came from a variety of sources including LexisNexis searches, news media accounts assembled by other commercial search services, web searches, reports from the US Consumer Product Safety Commission and the National Center for Catastrophic Sports Injury Research, and direct reports from schools and parents.

Of the total deaths included in the study, about 261 were caused by trauma, or around 9 deaths per year. 57% of the 261 deaths were in a single sport, football. Notably, there were about four times as many deaths due to cardiac causes as to trauma.

In football they find defensive positions have more deaths than offensive positions, "presumably because such players commonly initiate and deliver high-velocity blows while moving toward the point of contact." While the majority of deaths were in defensive players, the single most represented position was running backs.

Why the focus on deaths in young athletes? The authors note by comparison that lightning causes about 50 deaths per year, and motor vehicle injuries case 12,000 deaths per year. (Aside: You can tell the authors don't work in injury prevention since they say "motor vehicle accident" rather than "injury" -- injury prevention researchers prefer the latter terminology because they believe "accidental" deaths sound unavoidable.) The authors explain their own focus by noting that these sudden deaths attract "considerable media attention, with great importance to the physician and lay communities, particularly given the youthful age and apparent good health of the victims."

In related news: "The Ivy League [announced that...] in an effort to minimize head injuries among its football players, it will sharply reduce the number of allowable full-contact practices teams can hold."