Reproducibility in the Hematology Laboratory: One-stage Prothrombin Times

Bowyer, Frank P.; Stratos, Milton; Goldenfarb, Paul B.; Hall, Elmer C.

doi:10.1093/ajcp/57.4.482

Cited by 3 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bowyer et al (1971) [33] performed a nice study of variation in PT with the following sources: within-run, among-run (day) over 10 non-consecutive days, 2 fibrometers, 4 thromboplastins, and two lyophilized pools of citrated plasma with normal and prolonged PT. Sources of variation was estimated by analysis of variance.…”

Section: Studies On Analytical Variationmentioning

confidence: 99%

“…Although the analysis apparently was performed on raw PTs, which typically exhibit heteroscedasticity due to increasing variance with increasing levels of measurement, the study clearly demonstrated that there can be significant differences between PTs obtained with different thromboplastins and different types of instrumentation. Only means and standard deviations are given in [33], but from tables 1, 2 and 3 in the paper, the within-run and between-day coefficient of variations (CVs) can be estimated to be of the magnitude 2-3% and 3-4%, respectively. Leck et al, in 1974 [34], published results from 275 UK hospitals from 4 quality control trials.…”

Section: Studies On Analytical Variationmentioning

confidence: 99%

See 1 more Smart Citation

Monitoring Oral Anticoagulant Therapy

Tripodi

2008

Quality in Laboratory Hemostasis and Thrombosis

View full text Add to dashboard Cite

Since 1984, when I was matriculated as a medical student, I have taken an interest in all the three major areas, but my main occupation in the past 12 years has been with the quantitative epistemological discipline of statistics, which deals with the collection, analysis, interpretation, and presentation of numerical data. The formal foundation for theoretical statistics is mathematical statistics, in which I took a master's degree (MSc) in 1995.Concurrently, in the past nine years, and especially since 1995, when I was first employed at the Department of Biostatistics, I have been occupied with biostatistics, which focuses on the development and use of statistical methods to solve problems and to answer questions that arise in human biology and medicine. My experience has been within various scientific disciplines including different medical specialties, and in every case I have found that knowledge of the subject matter of the particular area is an important prerequisite in order to be able to communicate with the specialist.A remarkable feature of many of the scientific problems I have encountered as a biostatistician is their similarity! It is striking, and fascinating, how different scientific areas have encountered the same epistemological challenges and how they independently have invented almost the same (good or bad) strategies for dealing with the analysis and interpretation of data. Another striking feature is the difference in language and traditions, which hinders the different areas in communicating their epistemological problems and discoveries to each other. With this in mind I consider it the principal goal of biostatistics to 1) collect epistemological and cognitive problems and solutions from different subject matter areas of research; 2) distill the problems and solutions through the language of mathematical statistics; 3) present, analyze and discuss the problems and solutions in a general setting within the mathematical-statistical scientific community; and 4) translate possible solutions to the problems to the language and traditions of the particular subject matter disciplines.A major challenge as a biostatistician is the translation of solutions and suggestions from very general terms to terms which are recognized by the subject matter specialist. I hope that this dissertation will be judged on the scientific usefulness of its applications of general statistical methodology, rather than on its exact compliance with the language and traditions of the subject matter disciplines, which it involves.

show abstract

Section: Studies On Analytical Variationmentioning

confidence: 99%

Section: Studies On Analytical Variationmentioning

confidence: 99%

Monitoring Oral Anticoagulant Therapy

Tripodi

2008

Quality in Laboratory Hemostasis and Thrombosis

View full text Add to dashboard Cite

show abstract

Temperature and food availability alters the physiology and aerobic capacity of tambaqui (Colossoma macropomum)

Barroso

Almeida-Val

Val

2020

Comparative Biochemistry and Physiology Part A: Molecular &

View full text Add to dashboard Cite

Investigation and Standardization of Prothrombin Times in Chickens , ,

1975

View full text Add to dashboard Cite

This investigation was undertaken to standardize the determination of the one-stage prothrombin time for use with chickens. Homologous thromboplastin was essential and the most active thromboplastin was obtained from chickens four-weeks old or younger. Acetone-dried brain powder could be stored for at least 4 months at -15 degrees C. without loss of activity. Extraction of brain powder with 0.025 M CaCl2 at 42 degrees C. gave better thromboplastic activity than the standard extraction with physiological saline at room temperature. Thromboplastin solutions could be stored in ice water for only 6 hours without loss of activity. Citrate concentration had to be increased from the usual 0.10 M to 0.18 M to prevent premature clotting of plasma. Plasma donor age had no effect on the prothrombin times. Freezing and thawing as well as storage of plasma in the frozen state increased the prothrombin times. Using the best conditions, the mean prothrombin time for 1200 birds determined over a 6-month period was 9.4 sec. with an individual range of 7.18-11.4 sec. This represents a significantly lower prothrombin time with lower variability than that reported in the literature.

show abstract

Reproducibility in the Hematology Laboratory: One-stage Prothrombin Times

Cited by 3 publications

References 0 publications

Monitoring Oral Anticoagulant Therapy

Monitoring Oral Anticoagulant Therapy

Temperature and food availability alters the physiology and aerobic capacity of tambaqui (Colossoma macropomum)

Investigation and Standardization of Prothrombin Times in Chickens , ,

Contact Info

Product

Resources

About