Comparison of the Friedewald, Martin/Hopkins, and Sampson Equations for Calculating Low-Density Lipoprotein Cholesterol

Esra Paydaş Hataysal; Beyza Saraçlıgil

Article Details

Comparison of the Friedewald, Martin/Hopkins, and Sampson Equations for Calculating Low-Density Lipoprotein Cholesterol

Authors:

Esra Paydaş Hataysal | Beyza Saraçlıgil

Publisher:

Selcuk University

Main Topics:

Klinik Kimya

Journal:

Genel Tıp Dergisi Vol.35 Issue 4, pp.659-666

Document Type:

Article

Publication Date:

8/2025

Document Language:

English

Document ID (Org No.):

2001356605

pISSN:

2602-3741

Keywords:

Abstract:

 Abstract BackgroundAims: Ultracentrifugation, which is the reference method for low-density lipoprotein-cholesterol measurement, has been replaced by direct assays because it is not practical in standard clinical laboratories. However, due to the high cost and limited added value of direct assays, predictive equations are used. In this study, our aim was to compare the predictive performances of the Friedewald, MartinHopkins and Sampson equations to a direct assay when the triglyceride level is below 400 mgdL Methods: A total of 8,632 lipid profiles analyzed with Abbott Architect c8000 and c400 devices Abbott Laboratories, Abbott Park, IL, were included in the study. Those that misclassified patients based on low-density lipoprotein-cholesterol thresholds of 70 mgdL and 190 mgdL were identified as clinically relevant errors. Results: The percentage of results meeting desirable bias specifications 5.4 was 52.5, 58.2, and 56.2 in the Friedewald, MartinHopkins, and Sampson equations, respectively. The percentage of results meeting the total allowable error specifications 11.8 was 84, 89.1 and 87.7 in the Friedewald, MartinHopkins and Sampson equations, respectively. The Friedewald, MartinHopkins and Sampson equations showed negative proportional biases with a median bias of 2.3, -1.9 and -0.7, respectively. When triglyceride level was between 200399 mgdL, the median percentage bias was -8.2 for the Friedewald equation which exceeded the desirable bias criteria. The rates of clinically relevant errors for the Friedewald, MartinHopkins, and Sampson equations were 6, 4.9, and 5.5, respectively. Conclusions: Our comparative analysis of LDL-C estimation equations using the Abbott platform within the Turkish population reveals that while the MartinHopkins and Sampson equations exhibit only marginal differences in performance, both demonstrate superior accuracy relative to the Friedewald equation. Although the MartinHopkins yields marginally preferable outcomes, Sampson equation remains a clinically viable alternative.

 Abstract BackgroundAims: Ultracentrifugation, which is the reference method for low-density lipoprotein-cholesterol measurement, has been replaced by direct assays because it is not practical in standard clinical laboratories. However, due to the high cost and limited added value of direct assays, predictive equations are used. In this study, our aim was to compare the predictive performances of the Friedewald, MartinHopkins and Sampson equations to a direct assay when the triglyceride level is below 400 mgdL Methods: A total of 8,632 lipid profiles analyzed with Abbott Architect c8000 and c400 devices Abbott Laboratories, Abbott Park, IL, were included in the study. Those that misclassified patients based on low-density lipoprotein-cholesterol thresholds of 70 mgdL and 190 mgdL were identified as clinically relevant errors. Results: The percentage of results meeting desirable bias specifications 5.4 was 52.5, 58.2, and 56.2 in the Friedewald, MartinHopkins, and Sampson equations, respectively. The percentage of results meeting the total allowable error specifications 11.8 was 84, 89.1 and 87.7 in the Friedewald, MartinHopkins and Sampson equations, respectively. The Friedewald, MartinHopkins and Sampson equations showed negative proportional biases with a median bias of 2.3, -1.9 and -0.7, respectively. When triglyceride level was between 200399 mgdL, the median percentage bias was -8.2 for the Friedewald equation which exceeded the desirable bias criteria. The rates of clinically relevant errors for the Friedewald, MartinHopkins, and Sampson equations were 6, 4.9, and 5.5, respectively. Conclusions: Our comparative analysis of LDL-C estimation equations using the Abbott platform within the Turkish population reveals that while the MartinHopkins and Sampson equations exhibit only marginal differences in performance, both demonstrate superior accuracy relative to the Friedewald equation. Although the MartinHopkins yields marginally preferable outcomes, Sampson equation remains a clinically viable alternative.

 Abstract BackgroundAims: Ultracentrifugation, which is the reference method for low-density lipoprotein-cholesterol measurement, has been replaced by direct assays because it is not practical in standard clinical laboratories. However, due to the high cost and limited added value of direct assays, predictive equations are used. In this study, our aim was to compare the predictive performances of the Friedewald, MartinHopkins and Sampson equations to a direct assay when the triglyceride level is below 400 mgdL Methods: A total of 8,632 lipid profiles analyzed with Abbott Architect c8000 and c400 devices Abbott Laboratories, Abbott Park, IL, were included in the study. Those that misclassified patients based on low-density lipoprotein-cholesterol thresholds of 70 mgdL and 190 mgdL were identified as clinically relevant errors. Results: The percentage of results meeting desirable bias specifications 5.4 was 52.5, 58.2, and 56.2 in the Friedewald, MartinHopkins, and Sampson equations, respectively. The percentage of results meeting the total allowable error specifications 11.8 was 84, 89.1 and 87.7 in the Friedewald, MartinHopkins and Sampson equations, respectively. The Friedewald, MartinHopkins and Sampson equations showed negative proportional biases with a median bias of 2.3, -1.9 and -0.7, respectively. When triglyceride level was between 200399 mgdL, the median percentage bias was -8.2 for the Friedewald equation which exceeded the desirable bias criteria. The rates of clinically relevant errors for the Friedewald, MartinHopkins, and Sampson equations were 6, 4.9, and 5.5, respectively. Conclusions: Our comparative analysis of LDL-C estimation equations using the Abbott platform within the Turkish population reveals that while the MartinHopkins and Sampson equations exhibit only marginal differences in performance, both demonstrate superior accuracy relative to the Friedewald equation. Although the MartinHopkins yields marginally preferable outcomes, Sampson equation remains a clinically viable alternative.

 Özet GirişAmaç: Düşük yoğunluklu lipoprotein kolesterol LDL-K ölçümünde referans yöntem olan ultrasestrifügasyon, klinik laboratuvarlarda pratik olmaması nedeniyle yerini direk testlere bırakmıştır. Ancak direk testlerin yüksek maliyeti ve katkısının az olması nedeniyle LDL-K tahmin denklemleri kullanılmaktadır. Bu çalışmada amacımız, trigliserid düzeyi 400 mgdLnin altında olduğunda Friedewald, MartinHopkins ve Sampson denklemlerinin tahmin performanslarını bir direkt ölçüm yöntemiyle karşılaştırmaktır. Yöntemler: Çalışmaya, Abbott Architect c8000 ve c400 cihazları Abbott Laboratories, Abbott Park, IL ile analiz edilen toplam 8.632 lipid profili dahil edildi. LDL-K eşik değerleri olan 70 mgdL ve 190 mgdLye göre hastaları yanlış sınıflandıran durumlar klinik olarak anlamlı hata olarak kabul edildi. Bulgular: Desirable Bias kriterlerini 5,4 karşılayan sonuç yüzdesi sırasıyla Friedewald, MartinHopkins ve Sampson denklemlerinde 52,5, 58,2 ve 56,2 idi. Toplam izin verilebilir hata sınırlarını 11,8 karşılayan sonuç yüzdesi sırasıyla 84, 89,1 ve 87,7 olarak bulundu. Friedewald, MartinHopkins ve Sampson denklemleri negatif orantılı bias gösterdi; medyan bias sırasıyla 2,3, 1,9 ve 0,7 idi. Trigliserid düzeyinin 200399 mgdL arasında olduğu durumlarda, Friedewald denkleminin medyan yüzde biası 8,2 olarak bulundu ve bu değer desirable bias kriterlerini aşmıştır. Klinik olarak anlamlı hata oranları Friedewald, MartinHopkins ve Sampson denklemleri için sırasıyla 6, 4,9 ve 5,5 olarak belirlendi. Tartışma:Abbott platformu kullanılarak Türk popülasyonunda yapılan bu LDL-K tahmin denklemleri karşılaştırmasında, MartinHopkins ve Sampson denklemleri arasında yalnızca küçük farklar bulunmasına rağmen, her ikisi de Friedewald denklemine göre daha yüksek doğruluk göstermiştir. Sampson yöntemi sınırlı da olsa daha iyi sonuçlar verirken, MartinHopkins denklemi de klinik olarak geçerli bir alternatiftir.

Article Details

Comparison of the Friedewald, Martin/Hopkins, and Sampson Equations for Calculating Low-Density Lipoprotein Cholesterol

Authors:

Esra Paydaş Hataysal | Beyza Saraçlıgil

Publisher:

Selcuk University

Main Topics:

Klinik Kimya

Journal:

Genel Tıp Dergisi Vol.35 Issue 4, pp.659-666

Document Type:

Article

Publication Date:

8/2025

Document Language:

English

Document ID (Org No.):

2001356605

pISSN:

2602-3741

Low-Density Lipoprotein Cholesterol

Cardiovascular Disease

Friedewald Equation

BiasDüşük Yoğunluklu Lipoprotein Kolesterol

Kardiyovasküler Hastalık

Friedewald Denklemi

Bias

Issues

Article Details

Authors: Esra Paydaş Hataysal | Beyza Saraçlıgil

Publisher: Selcuk University

Main Topics: Klinik Kimya

Journal: Genel Tıp Dergisi Vol.35 Issue 4, pp.659-666

Document Type: Article

Publication Date: 8/2025

Document Language: English

Document ID (Org No.): 2001356605

pISSN: 2602-3741

Issues

Authors:

Esra Paydaş Hataysal | Beyza Saraçlıgil

Publisher:

Selcuk University

Main Topics:

Klinik Kimya

Journal:

Genel Tıp Dergisi Vol.35 Issue 4, pp.659-666

Document Type:

Article

Publication Date:

8/2025

Document Language:

English

Document ID (Org No.):

2001356605

pISSN:

2602-3741