title: Proficiency analytical testing (PAT) program.
authors.affiliation: Department of Health and Human Services, U.S. Public Health Service, Centers for Disease Control and Prevention, Cincinnati, OH 45226, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Esche
authors.forename: J H
authors.initials: JH
authors.lastname: Groff
mesh_terms: D002487:Centers for Disease Control and Prevention, U.S.; D004784:Environmental Monitoring / Q000592:standards*; D006801:Humans; D007753:Laboratories / Q000592:standards*; D009314:National Institute for Occupational Safety and Health, U.S.; D016272:Occupational Health; D011786:Quality Control; D012955:Societies, Medical; D017749:Total Quality Management; D014481:United States