The NFL has suspended its study of the long-term effects of concussions in retired players, The New York Times reported on Saturday.
The study began in 2007 and was to last through next year. It has been consistently criticized by the NFL player's union, outside experts and Congress because of the statistical sampling size and conflicts of interest, among other things.
The co-chairs of the league's committee on concussions, Dr. Ira Casson and Dr. David Viano, resigned in November after the retired-player study was ridiculed in a hearing before the House Judiciary Committee.
Casson, who performed every neurological exam, discredited evidence linking football to cognitive decline and dementia in retired players, The Times reported.
NFL spokesman Greg Aiello said in an e-mail message to The Times Friday that the study of retired players "is on hold for now as we explore having the study supported through an academic medical institution."