Martin SS, Blaha MJ, Elshazly MB, Toth PP, Kwiterovich PO, Blumenthal RS, Jones SR. Comparison of a novel method vs the Friedewald equation for estimating low-density lipoprotein cholesterol levels from the standard lipid profile. JAMA 2013;310:2061-8.

http://jama.jamanetwork.com/article.aspx?articleid=1779534

In conjunction with the published manuscript, we developed this website to provide free online access to automated calculation of LDL cholesterol by the Martin/Hopkins method using an Excel-based calculator or Stata .do file. It is anticipated that the primary use will be for research, whereas for clinical purposes the Martin/Hopkins can be directly integrated into lab IT systems or calculated using the free smartphone application available in the Apple App store and Google Play store. Rather than using a fixed factor of 5, the Martin/Hopkins calculation matches each person with an individualized factor to estimate VLDL cholesterol from triglycerides. The inputs are the three direct measures from the standard lipid profile: total cholesterol, HDL cholesterol, and triglycerides. LDL cholesterol is calculated in mg/dL as:

Total Cholesterol – HDL Cholesterol – Triglycerides/Individualized Factor

How to Use with Excel

  1. Organize your database such that there are three columns for total cholesterol, HDL cholesterol, and triglycerides (each in mg/dL), with each row representing an individual patient.
  2. Based on the number of rows in your database, download the fitting Excel file (i.e., if you have between 1000 and 2000 rows or patients, then download the “2k" version.)
  3. Copy the values for total cholesterol, HDL cholesterol, and triglycerides from your database into the Excel file; non-HDL-C, the novel factor, and LDL cholesterol by the Martin/Hopkins method, will each be automatically calculated.
  4. Copy this information back into your database, ensuring that the rows properly match each individual patient.

Download the Excel File

Since the speed of the Excel file depends on its size and the computer, we provide versions of various sizes. Select a file based on the number of rows or patients that you need to calculate. We have password-protected the functions in the calculator to ensure that they are not altered inadvertently.

Excel File Versions

How to Use with Stata

In your Stata dataset, label non-HDL-C (total cholesterol - HDL cholesterol) as "nonhdl" and triglycerides as "tg", then download and run the Stata .do file (link below). Two new variables will be created in your Stata dataset: 1) "factor" (the individualized conversion factor) and 2) "ldl180" (LDL-C by the Martin/Hopkins method).

Stata .do

Questions Please direct any questions to Seth S. Martin by email: smart100@jhmi.edu

Acknowledgment Many thanks to Dan Bodami, Satish Misra, Gorkem Sevinc, and Katie Hazard for their technical expertise in creating this website.

This Martin/Hopkins LDL-C calculation has been extensively validated and recommended as a preferred method for assessing LDL-C in clinical practice.

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