Short-Term and Long-Term Intra-Individual Variations and Critical Differences of Clinical Chemical Laboratory Parameters

Abstract

Summary: Twenty eight clinical chemical blood parameters were studied with respect to intra-individual variations. Both short tenn variations, within one day and during one week, and long term variations, during a six months period, were investigated in groups of 62, 16 and 274 individuals. Moreover, critical differences were calculated from the total variations, i.e. physiological (personal) and analytical variations. The influences of external factors (sex, smoking, and oral contraceptives) were been studied.It was concluded that the use of laboratory data in clinical diagnosis is considerably improved when intra-individual variations and critical differences are used. Kurz· und langzeitige intraindividuelle Änderungen sowie kritische Differenzen klinisch-chemischer KenngrößenZusammenfassung: Die intraindividuellen Änderungen von 28 klinisch-chemisch bestimmten Blutbestandteilen wurden untersucht. In Gruppen von 62,16 und 274 Probanden wurden sowohl kurzzeitige Änderungen innerhalb eines Tages und während einer Woche als auch langzeitige Änderungen während eines halben Jahres verfolgt. Zusätzlich.wurden aus den Gesamt-Änderungen, d.h. physiologischen (individuellen) und analytischen Variationen, kritische Differenzen berechnet. Weiterhin wurden äußere Einflüsse wie Geschlecht, Rauchen und Einnahme oraler Kontraceptiva untersucht.Aus den Ergebnissen wird geschlossen, daß die Verwendung von Labordaten in der klinischen Diagnostik wesentlich verbessert wird, wenn intraindividuelle Variationen und kritische Differenzen benutzt werden.

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