title: An artefact related to the ratio of sample volume to the blood collection vial size which effects the APTTs of specimens taken to monitor heparin therapy.
authors.forename: M J
authors.initials: MJ
authors.lastname: Ray
mesh_terms: D016477:Artifacts; D001800:Blood Specimen Collection / Q000295:instrumentation / Q000379:methods*; D006493:Heparin / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D008991:Monitoring, Physiologic; D010314:Partial Thromboplastin Time
chemical_list: D006493:Heparin