Original sentence: NICE claims none of the existing case definitions are based on robust evidence.The National Institute for Health and Clinical Excellence (NICE) in England and Wales discourages use of this "stringent" definition, challenging that the biology is not yet recognized and is thus judged as too restrictive
Edited sentence: The 2007 CFS/ME guideline, published by the National Institute for Health and Clinical Excellence (NICE) in England and Wales, states that none of the existing case definitions are based on robust evidence, and no studies have confimed any case definition to be superior to others