[Quality assurance of analytical methods to guarantee the reliability of medical decision levels for interpretation of clinical laboratory data].
We sought to investigate the effects of measurement errors on the evaluation of biological variations in healthy subjects. To this end, we analyzed the allowable limits of analytical error which can guarantee the reliability of medical decision levels for interpretation of clinical laboratory data. As a conclusion, we suggest that one-half or less of biological intra-individual variations is appropriate as the criterion for an allowable limit of error to be applied in health check-ups, and this value is in agreement with those in previous reports. If this criteria as the marker for intra-laboratory imprecision is met, a given institute should be able to evaluate time series change follow up of individual data. If the reference interval of laboratory data for disease screening is shared by different institutes, the criterion of 1/4 or less of a biological inter pulse intra-individual variation should be appropriate. This criterion appears to be the goal to be achieved for analytical inter-laboratory variations. On the other hand, as for the criterion for measurement errors which guarantees disease identification based on the cut-off value, a criterion of 1/4 or less of biological inter-pulse intra-individual variation appears to be appropriate, taking into consideration measurement errors which did not influence false-positive or false-negative rates of disease identification. The value turned out to be the same as the limit for the screening of disease. In this study, we considered allowable limits of error in the vicinity of reference value concentrations. However, it will be necessary to set separately the criteria for data in abnormal ranges.
Clinical Laboratory, University of Yamanashi Hospital, Nakakoma-gun, Yamanashi-pref. 409-3898.
Shigemi
S
Hosogaya
Yukio
Y
Ozaki
D019411:Clinical Laboratory Techniques / Q000592:standards*; D007206:Individuality; D015588:Observer Variation; D011785:Quality Assurance, Health Care / Q000379:methods*; D012016:Reference Values