A year-long report centered around mens and womens college hockey teams in Canada and the United States says coaches would rather keep players with possible head injuries playing than remove them from the game for a medical check.

The study, which was published as part of a series of articles in the journal Neurosurgical Focus, was conducted during the 2011-12 hockey season by researchers from the University of Western Ontario, the University of Montreal, Harvard and other institutions.

This culture is entrenched at all levels of hockey, from peewee to university, said Dr. Paul S. Echlin, a concussion specialist and researcher in Burlington, Ontario, and the lead author of the study, to the New York Times. Concussion is a significant public health issue that requires a generational shift. As with smoking or seat belts, it doesnt just happen overnight – it takes a massive effort and collective movement.

The study is believed to be among the most comprehensive analyses of concussions in hockey, which has a rate of head trauma approaching that of football.