The homeostatic model assessment (HOMA) is a method used to quantify insulin resistance

Insulin resistance

Insulin resistance is a physiological condition where the natural hormone insulin becomes less effective at lowering blood sugars. The resulting increase in blood glucose may raise levels outside the normal range and cause adverse health effects, depending on dietary conditions. Certain cell types...

 and beta-cell function. It was first described under the name HOMA by Matthews et al. in 1985.

Derivation

The HOMA authors used data from physiological studies to develop mathematical equations describing glucose regulation as a feedback loop.

They published computer software that solves the equations, so that insulin resistance and β-cell function can be estimated from fasting glucose and insulin levels. They also published an equation (see below) that gave approximately the same answers as an early version of the computer software.
The computer model has since been improved to a HOMA2 model to better reflect human physiology and recalibrated to modern insulin assays. In this updated version it is possible to determine insulin sensitivity and β-cell function from paired fasting plasma glucose and Radioimmunoassay

Radioimmunoassay

Radioimmunoassay is a very sensitive in vitro assay technique used to measure concentrations of antigens by use of antibodies...

insulin, specific insulin, or C-peptide concentrations. The authors recommend the computer software be used wherever possible.