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. 2025 Jun 13;44(3):479-485.
doi: 10.5937/jomb0-56100.

A comparison of the optical method with the mechanical method in routine coagulation tests

Gözde Ülfer  1
Affiliations

A comparison of the optical method with the mechanical method in routine coagulation tests

Gözde Ülfer. J Med Biochem. .

Abstract
in English, Serbian

Background: This study aimed to compare the prothrombin time (PT), international normalised ratio (INR) and activated partial thromboplastin time (aPTT) values obtained using the photo-optical method and to assess these values according to the reference method, which was the mechanical method.

Methods: Plasma samples from 340 patients, submitted to our hospital's biochemistry laboratory for PT, INR, and aPTT analyses, were assayed using the mechanical coagulometric measurement method in a Stago Compact Max3 automated coagulation analyser, which served as the reference device. The same samples were also analysed using the Sunbio UP5500 automated analyser with a simultaneous optical method. There were 30 turbid samples analysed in both devices without exclusion from the study. Correlation coefficient analysis was carried out using SPSS to assess intervariable correlations. Passing-Bablok regression analysis was performed in R software version 3.6.0 to compare PT, INR, and aPTT values between the two devices. Bland-Altman plots were used to analyse the agreement.

Results: A good level of statistically significant agreement was found between the PT and INR values measured by the Stago Compact Max3 and Sunbio UP 5500 devices (Interclass Coefficient Correlation (ICC): 0.627, p=0.001; p<0.01 and ICC: 0.653, p=0.001; p<0.01, respectively). Additionally, there was an excellent level of statistically significant agreement for the aPTT values (ICC: 0.902, p=0.001, p<0.01). The Bland-Altman analysis revealed the mean 95% limits of agreement values as 2.46 (lower limit: -2.44, upper limit: 7.37) for PT, 0.07 (lower limit: -0.32, upper limit: 0.46) for INR, and 2.45 (lower limit: -1.67, upper limit: 6.58) for aPTT. The Passing-Bablok regression results indicated a systematic difference for PT measurement but no proportional difference. No systematic or proportional differences were found for the measured INR and aPTT values between the Stago Compact Max3 and Sunbio UP 5500 devices. The intra-assay and interassay coefficient of variation (CV) values from level 1 and 2 controls of the optical method were below 5%.

Conclusions: The results from the optical method were consistent and reliable compared to the mechanical method. PT and INR results showed statistically good agreement, while aPTT results demonstrated excellent agreement. Larger multicenter studies are needed to evaluate turbid samples.

Uvod: Ova studija je imala za cilj da uporedi vrednosti protrombinskog vremena (PT), me|unarodnog normalizovanog odnosa (INR) i aktiviranog parcijalnog tromboplastinskog vremena (aPTT) dobijene foto-optičkom metodom i da proceni ove vrednosti u odnosu na referentnu, mehaničku metodu.

Metode: Plazma uzorci 340 pacijenata su poslati u biohemijsku laboratoriju naše bolnice na analizu PT, INR i aPTT, i ispitani su mehaničkom koagulometrijskom metodom merenja na automatskom koagulacionom analizatoru Stago Compact Max3, koji je poslužio kao referentni uređaj. Isti uzorci su takođe analizirani pomoću automatskog analizatora Sunbio UP5500 sa istovremenom optičkom metodom. Trideset zamućenih uzoraka je analizirano na oba uređaja bez isključivanja iz studije. Analiza koeficijenta korelacije izvršena je korišćenjem SPSS-a za procenu korelacija izme|u promenljivih, a Passing-Bablok regresiona analiza je izvedena u softveru R, verzija 3.6.0, za poređenje PT, INR i aPTT vrednosti između dva uređaja. Za analizu saglasnosti su korišćeni Bland-Altman grafici.

Rezultati: Utvrđen je dobar nivo statistički značajne saglasnosti između PT i INR vrednosti izmerenih na uređajima Stago Compact Max3 i Sunbio UP5500 (koeficijent intraklasne korelacije (ICC): 0,627, p=0,001; p<0,01 i ICC: 0,653, p=0,001; p<0,01, respektivno). Pored toga, za aPTT vrednosti postignut je izuzetan nivo statistički značajne saglasnosti (ICC: 0,902, p=0,001, p<0,01). Bland-Altman analiza je pokazala prosečne 95% granice saglasnosti sa vrednostima od 2,46 (donja granica: -2,44, gornja granica: 7,37) za PT, 0,07 (donja granica: -0,32, gornja granica: 0,46) za INR i 2,45 (donja granica: -1,67, gornja granica: 6,58) za aPTT. Rezultati Passing-Bablok regresione analize ukazali su na sistematsku razliku za merenje PT, ali bez proporcionalne razlike. Nisu pronađene sistematske ili proporcionalne razlike za merenje INR i aPTT vrednosti između uređaja Stago Compact Max3 i Sunbio UP5500. Koeficijenti varijacije (CV) unutar serije i između serija za nivoe 1 i 2 kontrole optičke metode bili su ispod 5%.

Zaključak: Rezultati optičke metode su se pokazali doslednim i pouzdanim u poređenju sa mehaničkom metodom. PT i INR rezultati pokazali su statistički dobru saglasnost, dok su aPTT rezultati pokazali izuzetnu saglasnost. Potrebne su veće multicentrične studije za evaluaciju zamućenih uzoraka.

Keywords: Bland-Altman plots; Passing-Bablok regression; coagulation tests; mechanic method; optic method.

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Conflict of interest statement

All the authors declare that they have no conflict of interest in this work.Conflict of Interest: The authors stated that they have no conflicts of interest regarding the publication of this article.

Figures

Figure 1
Figure 1. Comparison of tests by applying Bland-Altman plots and Passing-Bablok regression models. PT (A1, A2); INR (B1, B2); aPTT (C1, C2).
See this image and copyright information in PMC

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References

    1. Smythe M A, Priziola J, Dobesh P P, Wirth D, Cuker A, Wittkowsky A K. Guidance for the practical management of the heparin anticoagulants in the treatment of venous thromboembolism. J. Thromb. Thrombolysis. 2016;41(1):165. doi: 10.1007/s11239-015-1315-2. - DOI - PMC - PubMed
    1. Kaserer A, Casutt M, Sprengel K, Seifert B, Spahn D R, Stein P. Comparison of two different coagulation algorithms on the use of allogenic blood products and coagulation factors in severely injured trauma patients: a retrospective, multicentre, observational study. Scand J Trauma Resusc Emerg Med. 2018;26(1):1. doi: 10.1186/s13049-017-0463-0. - DOI - PMC - PubMed
    1. Mina A, Favaloro E J, Koutts J. Relationship between short activated partial thromboplastin times, thrombin generation, procoagulant factors and procoagulant phospholipid activity. Blood Coagul. Fibrinolysis. 2012;23(3):203. doi: 10.1097/mbc.0b013e32834fa7d6. - DOI - PubMed
    1. Rathod N, Nair S, Mammen J, Singh S. A comparison study of routine coagulation screening tests (PT and APTT) by three automated coagulation analyzers Int. J. Med Sci Public Heal. 2016 | https://www.cabidigitallibrary.org/doi/full/10.5555/20163297066;5(8):1563. doi: 10.5455/ijmsph.2016.13112015254. - DOI
    1. Basok B I, Kocakoc I D, Iyilikci V, Kantarmaci S, Fidan M. Forecasting the consumptions of coagulation tests using a deep learning model. J Med Biochem. 2024;43(4):372. doi: 10.5937/jomb0-40244. - DOI - PMC - PubMed

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