PMID- 34292121
OWN - NLM
STAT- MEDLINE
DCOM- 20211015
LR  - 20240403
IS  - 1943-4936 (Electronic)
IS  - 1040-6387 (Print)
IS  - 1040-6387 (Linking)
VI  - 33
IP  - 5
DP  - 2021 Sep
TI  - Validation study of canine serum cortisol measurement with the Immulite 2000 Xpi 
      cortisol immunoassay.
PG  - 844-863
LID - 10.1177/10406387211029247 [doi]
AB  - We report the results of validation of canine serum cortisol determination with 
      the Immulite 2000 Xpi cortisol immunoassay (Siemens), with characterization of 
      precision (CV), accuracy (spiking-recovery [SR] bias), and observed total error 
      (TEo = bias + 2CV) across the reportable range, specifically at the most common 
      interpretation thresholds for dynamic testing. Imprecision increased at 
      increasing rate with decreasing serum cortisol concentration and bias was low, 
      resulting in increasing TEo with decreasing serum cortisol concentration. 
      Inter-laboratory comparison study allowed for determination of range-based bias 
      (RB) and average bias (AB). At 38.6 and 552 nmol/L (1.4 and 20 mug/dL), 
      between-run CV was 10% and 7.5%, respectively, and TEo ~30% and ~20%, 
      respectively (TEo remained similar regardless of the considered bias: SR, RB, or 
      AB). These analytical performance parameters should be considered in the 
      interpretation of results and for future expert consensus discussions to 
      determine recommendations for allowable total error (TEa). Importantly, the 
      commonly used thresholds for interpretation of results were determined ~40 y ago 
      with different methods of measurements and computation, hence updating is 
      desirable. Quality control material (QCM) had between-run imprecision of 4% for 
      QCM1 and 7% for QCM2; the bias was minimal for both levels. Acceptable QC rules 
      are heavily dependent on the desired TEa for the QCM system (TEa(QCM)), itself 
      limited by the desired clinical TEa. At low TEa(QCM) (20-33%), almost no rules 
      were acceptable, whereas at high TEa(QCM) (50%), almost all rules were 
      acceptable; further investigation is needed to determine which TEa(QCM) can be 
      guaranteed by simple QC rules.
FAU - Korchia, Jeremie
AU  - Korchia J
AUID- ORCID: 0000-0002-9344-6639
AD  - Texas A&M Veterinary Medical Diagnostic Laboratory, Texas A&M University, College 
      Station, TX, USA.
FAU - Freeman, Kathleen P
AU  - Freeman KP
AUID- ORCID: 0000-0003-1796-0158
AD  - SYNLAB-VPG/Exeter, Exeter, United Kingdom.
LA  - eng
PT  - Journal Article
DEP - 20210722
PL  - United States
TA  - J Vet Diagn Invest
JT  - Journal of veterinary diagnostic investigation : official publication of the 
      American Association of Veterinary Laboratory Diagnosticians, Inc
JID - 9011490
RN  - WI4X0X7BPJ (Hydrocortisone)
SB  - IM
MH  - Animals
MH  - Dogs
MH  - *Hydrocortisone
MH  - Immunoassay/veterinary
PMC - PMC8366243
OTO - NOTNLM
OT  - Cushing
OT  - accuracy
OT  - bias
OT  - cortisol
OT  - dogs
OT  - endocrinology
OT  - precision
OT  - total error
COIS- Declaration of conflicting interests: The authors declared no potential conflicts 
      of interest with respect to the research, authorship, and/or publication of this 
      article.
EDAT- 2021/07/23 06:00
MHDA- 2021/10/16 06:00
PMCR- 2022/07/22
CRDT- 2021/07/22 12:19
PHST- 2021/07/23 06:00 [pubmed]
PHST- 2021/10/16 06:00 [medline]
PHST- 2021/07/22 12:19 [entrez]
PHST- 2022/07/22 00:00 [pmc-release]
AID - 10.1177_10406387211029247 [pii]
AID - 10.1177/10406387211029247 [doi]
PST - ppublish
SO  - J Vet Diagn Invest. 2021 Sep;33(5):844-863. doi: 10.1177/10406387211029247. Epub 
      2021 Jul 22.