What is nefarious, or at least extremely sloppy, is that the paper's authors claimed prominently that they had captured all of the data on every concussion in t

What is nefarious, or at least extremely sloppy, is that the paper's authors claimed prominently that they had captured all of the data on every concussion in the NFL within the time period. Also, they included the games played by the teams that provided no data in the total, which therefore reduced the incidence rate of head injuries in their final analysis. From a companion article in NYT: “It was understood that any player with a recognized symptom of head injury, no matter how minor, should be included in the study,” one paper said. And in confidential peer-review documents, the committee wrote that “all N.F.L. teams participated” and that “all players were therefore part of this study.”