TY - JOUR
T1 - Estimating short- and long-term reference change values and index of individuality for tests of platelet function
AU - Katzman, Brooke M.
AU - Wockenfus, Amy M.
AU - Scott, Renee J.
AU - Bryant, Sandra C.
AU - Jaffe, Allan S.
AU - Karon, Brad S.
N1 - Funding Information:
This publication was made possible by CTSA Grant Number UL1 TR002377 from the National Center for Advancing Translational Sciences (NCATS), a component of the National Institutes of Health (NIH). Its contents are solely the responsibility of the authors and do not necessarily represent the official view of NIH. Brooke M. Katzman, Amy M. Wockenfus, Renee J. Scott, Sandra C. Bryant, Allan S. Jaffe and Brad S. Karon declare no conflicts of interest and have no financial disclosures relevant to the study. Appendix A
Publisher Copyright:
© 2019 The Canadian Society of Clinical Chemists
PY - 2019/12
Y1 - 2019/12
N2 - Background: In order to manage risks of bleeding and thrombosis after some surgical procedures, platelet function is often measured repeatedly over days or weeks using laboratory tests of platelet function. To interpret test results in the perioperative period, it is necessary to understand analytical, biological and between-person variation. Methods: We collected three separate blood specimens from 16 healthy volunteers on the first study day, and one additional specimen from each volunteer 1, 2, and 3 months later. Arachidonic acid-induced and adenosine diphosphate (ADP)-induced platelet function were measured in duplicate by whole blood impedance aggregometry using Multiplate (ASPI/ADP tests) and VerifyNow (Aspirin Reaction Units [ARU] and P2Y12 Reaction Units [PRU]). The analytical variation (CVA), within-subject variation (CVI), between-subject variation (CVG), index of individuality (II), and reference change values (RCV) were calculated. Results: VerifyNow ARU demonstrated the smallest short-term and long-term variability (CVA, CVI, and CVG ~1%), resulting in short- and long-term RCV values <5%. II was also higher (1.92) for VerifyNow ARU than other platelet function tests. Multiplate ASPI and ADP tests had the highest RCV both short-(19.0% and 25.2%, respectively) and long-term (32.1% and 39.6%, respectively) due to increased CVA (>5%) and CVI (3.9–13.1%). VerifyNow PRU had a lower RCV than Multiplate ADP; but was the only test with II <0.6. Conclusions: VerifyNow ARU results can be interpreted relative to a fixed cut-off or population-based reference interval; or relative to small changes in an individual's previous values. VerifyNow PRU and Multiplate ASPI and ADP tests should only be interpreted based upon relative change; and can only distinguish relatively large (>23%) changes over several weeks.
AB - Background: In order to manage risks of bleeding and thrombosis after some surgical procedures, platelet function is often measured repeatedly over days or weeks using laboratory tests of platelet function. To interpret test results in the perioperative period, it is necessary to understand analytical, biological and between-person variation. Methods: We collected three separate blood specimens from 16 healthy volunteers on the first study day, and one additional specimen from each volunteer 1, 2, and 3 months later. Arachidonic acid-induced and adenosine diphosphate (ADP)-induced platelet function were measured in duplicate by whole blood impedance aggregometry using Multiplate (ASPI/ADP tests) and VerifyNow (Aspirin Reaction Units [ARU] and P2Y12 Reaction Units [PRU]). The analytical variation (CVA), within-subject variation (CVI), between-subject variation (CVG), index of individuality (II), and reference change values (RCV) were calculated. Results: VerifyNow ARU demonstrated the smallest short-term and long-term variability (CVA, CVI, and CVG ~1%), resulting in short- and long-term RCV values <5%. II was also higher (1.92) for VerifyNow ARU than other platelet function tests. Multiplate ASPI and ADP tests had the highest RCV both short-(19.0% and 25.2%, respectively) and long-term (32.1% and 39.6%, respectively) due to increased CVA (>5%) and CVI (3.9–13.1%). VerifyNow PRU had a lower RCV than Multiplate ADP; but was the only test with II <0.6. Conclusions: VerifyNow ARU results can be interpreted relative to a fixed cut-off or population-based reference interval; or relative to small changes in an individual's previous values. VerifyNow PRU and Multiplate ASPI and ADP tests should only be interpreted based upon relative change; and can only distinguish relatively large (>23%) changes over several weeks.
KW - Biological variation
KW - Index of individuality
KW - Platelet function test
KW - Relative change value
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U2 - 10.1016/j.clinbiochem.2019.10.001
DO - 10.1016/j.clinbiochem.2019.10.001
M3 - Article
C2 - 31669512
AN - SCOPUS:85074881999
SN - 0009-9120
VL - 74
SP - 54
EP - 59
JO - Clinical Biochemistry
JF - Clinical Biochemistry
ER -