PMID- 21958344
OWN - NLM
STAT- MEDLINE
DCOM- 20130920
LR  - 20220321
IS  - 1437-4331 (Electronic)
IS  - 1434-6621 (Linking)
VI  - 50
IP  - 5
DP  - 2011 Sep 30
TI  - Reference change values.
PG  - 807-12
LID - /j/cclm.2012.50.issue-5/cclm.2011.733/cclm.2011.733.xml [pii]
LID - 10.1515/CCLM.2011.733 [doi]
AB  - Reference change values (RCV) provide objective tools for assessment of the 
      significance of differences in serial results from an individual. The concept is 
      simple and the calculation easy, since all laboratories know their analytical 
      imprecision (CV(A)) and estimates of within-subject biological variation (CV(I)) 
      are available for a large number of quantities. Generally, CV(I) are constant 
      over time, geography, methodology and in health and chronic stable disease. The 
      formula is RCV=2(1/2) . Z . (CV(A)(2) + CV(I)(2))(1/2), where Z is the number of 
      standard deviations appropriate to the probability. Correct interpretation of the 
      semantics describing the clinical use of RCV is vital for selection of the 
      Z-score. Many quantities of clinically importance exist for which good estimates 
      of RCV are unavailable. Derivation of CV(I) may be difficult for such quantities: 
      flair and imagination are required in selecting populations with chronic but 
      stable disease on whom CV(I) can be determined. RCV can be used for 
      delta-checking and auto-verification and laboratory information management 
      systems (LIMS) can be adapted to do this. Recently, log-normal transformation to 
      obtain unidirectional RCV has been used. Gaps in knowledge of RCV still require 
      filling since the need for measures of change is clearly expressed in guidelines.
FAU - Fraser, Callum G
AU  - Fraser CG
AD  - Centre for Research into Cancer Prevention and Screening, University of Dundee, 
      Ninewells Hospital and Medical School, Dundee, Scotland, UK. 
      callum.fraser@nhs.net
LA  - eng
PT  - Journal Article
PT  - Review
DEP - 20110930
PL  - Germany
TA  - Clin Chem Lab Med
JT  - Clinical chemistry and laboratory medicine
JID - 9806306
SB  - IM
CIN - Clin Chem Lab Med. 2012 May;50(5):961; author reply 963-4. PMID: 22628320
MH  - Clinical Laboratory Techniques/*standards
MH  - Humans
MH  - Reference Values
EDAT- 2011/10/01 06:00
MHDA- 2013/09/21 06:00
CRDT- 2011/10/01 06:00
PHST- 2011/09/07 00:00 [received]
PHST- 2011/09/08 00:00 [accepted]
PHST- 2011/10/01 06:00 [entrez]
PHST- 2011/10/01 06:00 [pubmed]
PHST- 2013/09/21 06:00 [medline]
AID - /j/cclm.2012.50.issue-5/cclm.2011.733/cclm.2011.733.xml [pii]
AID - 10.1515/CCLM.2011.733 [doi]
PST - epublish
SO  - Clin Chem Lab Med. 2011 Sep 30;50(5):807-12. doi: 10.1515/CCLM.2011.733.