Comparison of reference intervals derived by direct and indirect methods based on compatible datasets obtained in Turkey

TY - JOUR

T1 - Comparison of reference intervals derived by direct and indirect methods based on compatible datasets obtained in Turkey

AU - Ozarda, Yesim

AU - Ichihara, Kiyoshi

AU - Jones, Graham

AU - Streichert, Thomas

AU - Ahmadian, Robab

AU - IFCC Committee on Reference intervals and Decision Limits (C-RIDL)

N1 - Crown Copyright © 2021. Published by Elsevier B.V. All rights reserved.

PY - 2021/9

Y1 - 2021/9

N2 - BACKGROUND: Indirect derivation of reference intervals (RIs) from the laboratory information system (LIS) has been recently pursued. We aimed at evaluating the accuracy of indirectly predicted RIs compared to the RIs established directly from healthy subjects in the nationwide RI study in Turkey, targeting 25 major chemistry analytes.METHODS: LIS data were retrieved from the laboratory that performed measurements for the direct study. They were cleaned by limiting to outpatients with age 18-65 years, and by allowing only one record per year per patient. Evaluated were four indirect methods of univariate approach: Hoffmann, Bhattacharya, Arzideh, and Wosniok methods. Power transformation of the LIS dataset was performed either using the power (λ) reported by the IFCC global RI study (the first two methods) or using a λ predicted (the last two).RESULTS: Compared to the direct study dataset, the LIS dataset showed a variable degree of alterations in peak location and shape. Consequently, lower-side peak-shifts observed in sodium, albumin, etc. led to lowered RI limits, whereas higher-side peak-shift observed in triglyceride, low-density lipoprotein cholesterol, etc. led to raised RI limits. Overall, 72% (62-81) of the RI limits predicted by indirect methods showed significant biases from direct RIs. However, the biases observed in total cholesterol, lactic dehydrogenase, etc. were attributed to a higher-side age-bias in LIS dataset. After excluding them, the overall proportion of biased RIs was reduced to 47% (38-54).CONCLUSION: To reduce prediction biases that remained after age adjustment, it is necessary to apply more rigorous data-cleaning before applying indirect methods.

AB - BACKGROUND: Indirect derivation of reference intervals (RIs) from the laboratory information system (LIS) has been recently pursued. We aimed at evaluating the accuracy of indirectly predicted RIs compared to the RIs established directly from healthy subjects in the nationwide RI study in Turkey, targeting 25 major chemistry analytes.METHODS: LIS data were retrieved from the laboratory that performed measurements for the direct study. They were cleaned by limiting to outpatients with age 18-65 years, and by allowing only one record per year per patient. Evaluated were four indirect methods of univariate approach: Hoffmann, Bhattacharya, Arzideh, and Wosniok methods. Power transformation of the LIS dataset was performed either using the power (λ) reported by the IFCC global RI study (the first two methods) or using a λ predicted (the last two).RESULTS: Compared to the direct study dataset, the LIS dataset showed a variable degree of alterations in peak location and shape. Consequently, lower-side peak-shifts observed in sodium, albumin, etc. led to lowered RI limits, whereas higher-side peak-shift observed in triglyceride, low-density lipoprotein cholesterol, etc. led to raised RI limits. Overall, 72% (62-81) of the RI limits predicted by indirect methods showed significant biases from direct RIs. However, the biases observed in total cholesterol, lactic dehydrogenase, etc. were attributed to a higher-side age-bias in LIS dataset. After excluding them, the overall proportion of biased RIs was reduced to 47% (38-54).CONCLUSION: To reduce prediction biases that remained after age adjustment, it is necessary to apply more rigorous data-cleaning before applying indirect methods.

KW - Adolescent

KW - Adult

KW - Aged

KW - Clinical Laboratory Information Systems

KW - Healthy Volunteers

KW - Humans

KW - Middle Aged

KW - Reference Values

KW - Turkey

KW - Young Adult

U2 - 10.1016/j.cca.2021.05.030

DO - 10.1016/j.cca.2021.05.030

M3 - SCORING: Journal article

C2 - 34081933

VL - 520

SP - 186

EP - 195

JO - CLIN CHIM ACTA

JF - CLIN CHIM ACTA

SN - 0009-8981

ER -