Effective February 1, 2021, the National Institutes of Health (NIH) equation (below) will replace the Friedewald equation for all lipid panels that report calculated low-density lipoprotein cholesterol (LDL-C) (1,2). The NIH calculation provides a more accurate LDL-C result than the Friedewald equation, particularly in patients with low LDL-C concentrations (< 70 mg/dL) (1,2). The NIH equation gives valid LDL-C results with triglyceride (TG) concentrations up to 800 mg/dL (1,2). When the triglyceride concentration is >800 mg/dL, the LDL-C will not be calculated, and a direct LDL-C should be ordered.
The NIH equation performs equally well in both fasting and non-fasting states.