The partial thromboplastin time in the CAP survey program.
Analysis of the data for the 1969 to 1973 CAP Surveys of proficiency in partial thromboplastin time (PTT) determination indicates more than desirable variability in this measurement. Non-activated procedures show greater interlaboratory variability than activated methods; therefore, they may be preferable for routine use. It is likely that many laboratories have not determined their own upper limit of normal for their PTT system and thus have received unacceptable evaluations in the Surveys. It also was determined that many laboratories do not closely follow the manufacturer's directions, especially in regard to incubation times and calcium concentration of the recalcification solution.
D001780:Blood Coagulation Tests / Q000592:standards*; D005169:Factor VIII / Q000032:analysis; D006467:Hemophilia A / Q000097:blood; D006801:Humans; D007753:Laboratories / Q000592:standards; D010336:Pathology; D012955:Societies, Medical; D013925:Thromboplastin; D013997:Time Factors; D014481:United States
D005169:Factor VIII; D013925:Thromboplastin