eGFR (Estimated Glomerular Filtration Rate): This is plotted on one axis and represents the kidney's filtering capacity. It is usually measured in milliliters per minute per 1.73 m². The eGFR is divided into categories (G1 to G5), with G1 being normal or high kidney function and G5 indicating kidney failure.

Albuminuria: This is plotted on the other axis and measures the amount of albumin (a type of protein) in the urine. It is an indicator of kidney damage. Albuminuria is divided into categories (A1 to A3), with A1 being normal to mildly increased and A3 being severely increased.

Color Coding:

The heat map uses a color-coded system to indicate the risk level associated with different combinations of eGFR and albuminuria. The colors typically range from:

• Green (low risk)
• Yellow (moderate risk)
• Orange (high risk)
• Red (very high risk)

Each cell in the heat map corresponds to a specific combination of eGFR and albuminuria, providing a visual representation of the patient's risk level.

Reference: Levey AS, Stevens LA, Schmid CH, et al. A new equation to estimate glomerular filtration rate. Ann Intern Med. 2009 May 5;150(9):604-612. doi:10.7326/0003-4819-150-9-200905050-00006. PMID:19414839.