title: Trial registration: must take place before or at the onset of enrolment.
authors.forename: Steve
authors.initials: S
authors.lastname: Goodacre
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage*; D000700:Analgesics / Q000008:administration & dosage*; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007660:Ketoprofen / Q000008:administration & dosage / Q000031:analogs & derivatives*; D017116:Low Back Pain / Q000188:drug therapy*; D008297:Male; D008881:Migraine Disorders / Q000188:drug therapy*; D009020:Morphine / Q000008:administration & dosage*; D014325:Tromethamine / Q000008:administration & dosage*
chemical_list: D000700:Analgesics; D018712:Analgesics, Non-Narcotic; D000894:Anti-Inflammatory Agents, Non-Steroidal; D014325:Tromethamine; D000082:Acetaminophen; D009020:Morphine; D007660:Ketoprofen; C118296:dexketoprofen trometamol
keywords: research, methods