TY - JOUR
T1 - Should we depend on reference intervals from manufacturer package inserts? Comparing TSH and FT4 reference intervals from four manufacturers with results from modern indirect methods and the direct method
AU - Dirks, Niek F.
AU - den Elzen, Wendy P. J.
AU - Hillebrand, Jacquelien J.
AU - Jansen, Heleen I.
AU - Boekel, Edwin Ten
AU - Brinkman, Jacoline
AU - Buijs, Madelon M.
AU - Demir, Ayse Y.
AU - Dijkstra, Ineke M.
AU - Endenburg, Silvia C.
AU - Engbers, Paula
AU - Gootjes, Jeannette
AU - Janssen, Marcel J. W.
AU - Kniest-de Jong, Wilhelmina H. A.
AU - Kok, Maarten B.
AU - Kamphuis, Stephan
AU - Kruit, Adrian
AU - Michielsen, Etienne
AU - Wolthuis, Albert
AU - Boelen, Anita
AU - Heijboer, Annemieke C.
N1 - Publisher Copyright: © 2024 the author(s), published by De Gruyter, Berlin/Boston.
PY - 2024/6/1
Y1 - 2024/6/1
N2 - Objectives: Correct interpretation of thyroid function tests relies on correct reference intervals (RIs) for thyroid-stimulating hormone (TSH) and free thyroxine (FT4). ISO15189 mandates periodic verification of RIs, but laboratories struggle with cost-effective approaches. We investigated whether indirect methods (utilizing historical laboratory data) could replace the direct approach (utilizing healthy reference individuals) and compared results with manufacturer-provided RIs for TSH and FT4. Methods: We collected historical data (2008-2022) from 13 Dutch laboratories to re-establish RIs by employing indirect methods, TMC (for TSH) and refineR (for FT4). Laboratories used common automated platforms (Roche, Abbott, Beckman or Siemens). Indirect RIs (IRIs) were determined per laboratory per year and clustered per manufacturer (>1.000.000 data points per manufacturer). Direct RIs (DRIs) were established in 125 healthy individuals per platform. Results: TSH IRIs remained robust over the years for all manufacturers. FT4 IRIs proved robust for three manufacturers (Roche, Beckman and Siemens), but the IRI upper reference limit (URL) of Abbott showed a decrease of 2pmol/L from 2015. Comparison of the IRIs and DRIs for TSH and FT4 showed close agreement using adequate age-stratification. Manufacturer-provided RIs, notably Abbott, Roche and Beckman exhibited inappropriate URLs (overall difference of 0.5-1.0μIU/mL) for TSH. For FT4, the URLs provided by Roche, Abbott and Siemens were overestimated by 1.5-3.5pmol/L. Conclusions: These results underscore the importance of RI verification as manufacturer-provided RIs are often incorrect and RIs may not be robust. Indirect methods offer cost-effective alternatives for laboratory-specific or platform-specific verification of RIs.
AB - Objectives: Correct interpretation of thyroid function tests relies on correct reference intervals (RIs) for thyroid-stimulating hormone (TSH) and free thyroxine (FT4). ISO15189 mandates periodic verification of RIs, but laboratories struggle with cost-effective approaches. We investigated whether indirect methods (utilizing historical laboratory data) could replace the direct approach (utilizing healthy reference individuals) and compared results with manufacturer-provided RIs for TSH and FT4. Methods: We collected historical data (2008-2022) from 13 Dutch laboratories to re-establish RIs by employing indirect methods, TMC (for TSH) and refineR (for FT4). Laboratories used common automated platforms (Roche, Abbott, Beckman or Siemens). Indirect RIs (IRIs) were determined per laboratory per year and clustered per manufacturer (>1.000.000 data points per manufacturer). Direct RIs (DRIs) were established in 125 healthy individuals per platform. Results: TSH IRIs remained robust over the years for all manufacturers. FT4 IRIs proved robust for three manufacturers (Roche, Beckman and Siemens), but the IRI upper reference limit (URL) of Abbott showed a decrease of 2pmol/L from 2015. Comparison of the IRIs and DRIs for TSH and FT4 showed close agreement using adequate age-stratification. Manufacturer-provided RIs, notably Abbott, Roche and Beckman exhibited inappropriate URLs (overall difference of 0.5-1.0μIU/mL) for TSH. For FT4, the URLs provided by Roche, Abbott and Siemens were overestimated by 1.5-3.5pmol/L. Conclusions: These results underscore the importance of RI verification as manufacturer-provided RIs are often incorrect and RIs may not be robust. Indirect methods offer cost-effective alternatives for laboratory-specific or platform-specific verification of RIs.
KW - direct method
KW - indirect method
KW - reference intervals
KW - thyroid disease
UR - http://www.scopus.com/inward/record.url?scp=85183682856&partnerID=8YFLogxK
U2 - 10.1515/cclm-2023-1237
DO - 10.1515/cclm-2023-1237
M3 - Article
C2 - 38205847
SN - 1434-6621
VL - 62
SP - 1352
EP - 1361
JO - Clinical chemistry and laboratory medicine
JF - Clinical chemistry and laboratory medicine
IS - 7
ER -