New techniques witch diminish the necessary number of normal patients' results in the "Average of Normals method"

dc.contributor.author	Καρκαλούσος, Πέτρος	el
dc.contributor.author	Ψαράκης, Σ.	el
dc.date.accessioned	2015-05-02T18:45:10Z
dc.date.issued	2015-05-02
dc.identifier.uri	http://hdl.handle.net/11400/9499
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ηνωμένες Πολιτείες	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/us/	*
dc.source	http://users.teiath.gr/petef/Web_CV/Presentations/Pre_AON_EWMA_2007.htm	el
dc.source	http://www.bclf.info/	el
dc.subject	Quality control method
dc.subject	Medical software
dc.subject	Μέθοδοι ελέγχου ποιότητας
dc.subject	Ιατρικό λογισμικό
dc.title	New techniques witch diminish the necessary number of normal patients' results in the "Average of Normals method"	en
heal.type	conferenceItem
heal.classification	Medicine
heal.classification	Technology
heal.classification	Ιατρική
heal.classification	Τεχνολογία
heal.classificationURI	http://id.loc.gov/authorities/subjects/sh00006614
heal.classificationURI	http://zbw.eu/stw/descriptor/10470-6
heal.classificationURI	N/A-Ιατρική
heal.classificationURI	N/A-Τεχνολογία
heal.dateAvailable	10000-01-01
heal.language	en
heal.access	forever
heal.recordProvider	Σχολή Επαγγελμάτων Υγείας και Πρόνοιας. Τμήμα Ιατρικών Εργαστηρίων	el
heal.publicationDate	2007
heal.bibliographicCitation	Karkalousos, P. and Psarakis, S. (2007) New techniques witch diminish the necessary number of normal patients' results in the "Average of Normals method". In "15th Balkan Conference of Clinical Chemistry". Attalya: Balkan Clinical Laboratory Federation.	en
heal.abstract	Introduction: The “Average Of Normals” (AON) method is an alternative quality control method based exclusively on patient’s data. According to it, the average of the daily normal results must be varied within certain limits, if not, it consists an analytical systematic error. The most important parameter of AON method is the necessary number (Nnec) of normal results for which their mean value can be used as a substitute of the common control samples. Former studies have proved that this number depends on the ratio Sp/Sa where Sp is the variance between health people and Sa is the analytical variance. Purpose: To diminish Nnec by using Westgard criteria and Exponential Weighted Moving Average Control Chart (EWMA). Method: A specific software is constructed based on a large number of simulations according to different analytes, Nnec, Sp, Sa, control chart limits (L) and the truncation limits (T) of the normal results. The program can also simulate the Westgard criteria suitable for systematic errors (22s, 10x, 41s) and the EWMA. In the last case the simulations refer to different weight factors (λ) and number of results for each moving average (n). Results: Many different ratios Sp/Sa were studied. For instance, for Sp/Sa = 8, Systematic error = 2, L= 3, T = 2, the application of 10x rule needs 50 normal results, 41s needs 90 normal results and 22s needs 175 normal results per day. On the contrary, 13S needs 275 normal results and 12,5S needs 200 normal results per day. Unfortunately, EWMA did not give so ambitious results. For the same simulations’ parameters including λ = 0,2 and n = 20, there will be needed more than 400 normal results. Conclusions: If the Westgard criteria are carried out on successive days, they diminish Nnec making AON method suitable even for laboratories with small turnover. This does not happen with EWMA method which does not diminish Nnec at all.	en
heal.publisher	Balkan Clinical Laboratory Federation	en
heal.fullTextAvailability	false
heal.conferenceName	15th Balkan Conference of Clinical Chemistry	en
heal.conferenceItemType	abstract