title: Twenty-five years of proficiency testing for clinical laboratories.
mesh_terms: D001663:Bilirubin / Q000592:standards; D001774:Blood Chemical Analysis / Q000592:standards; D001826:Body Fluids / Q000032:analysis; D002624:Chemistry, Clinical / Q000266:history* / Q000592:standards; D002784:Cholesterol / Q000592:standards; D003404:Creatinine / Q000592:standards; D005069:Evaluation Studies as Topic; D006077:Government Agencies; D006454:Hemoglobins / Q000592:standards; D049673:History, 20th Century; D006801:Humans; D007753:Laboratories / Q000592:standards*; D007878:Legislation as Topic; D010336:Pathology; D011786:Quality Control; D012952:Societies; D012955:Societies, Medical; D014481:United States; D014508:Urea / Q000592:standards; D014527:Uric Acid / Q000592:standards
chemical_list: D006454:Hemoglobins; D014527:Uric Acid; D014508:Urea; D002784:Cholesterol; D003404:Creatinine; D001663:Bilirubin