ToolsCalculators
Nutritional Risk Index (NRI)
Quantifies malnutrition risk from serum albumin and recent weight change before surgery.
Nutritional Risk Index (NRI)
Serum albumin
Current weight
Usual (baseline) weight
Complete the fields above to see the result.
When to use
- Estimating perioperative malnutrition risk, e.g. to identify surgical patients who may benefit from nutrition support.
Formula
NRI = 1.519 x serum albumin (g/L) + 41.7 x (current weight / usual weight), where the weight ratio is capped at 1 if current weight exceeds usual weight. >100 no risk, 97.5-100 mild, 83.5-<97.5 moderate, <83.5 severe.
Pearls and pitfalls
- Requires a reliable usual (pre-illness) weight; unreliable if usual weight is unknown or the patient is edematous.
- If current weight exceeds usual weight, the weight ratio is capped at 1.0 - weight gain above baseline does not further lower malnutrition risk in this formula.
- Albumin is also depressed by inflammation independent of nutritional status, which can overestimate risk in acute illness.