cliot (version 1.0.0)

nri_score: Nutritional Risk Index (NRI)

Description

Calculates the Nutritional Risk Index (NRI) to assess the extent of malnutrition in patients, particularly in surgical or elderly populations. The score uses serum albumin levels and the ratio of current to usual body weight to stratify patients into risk categories.

Usage

nri_score(albumin_g_dl, current_weight_kg, usual_weight_kg)

Value

A list containing:

NRI_Score

The calculated index value.

Risk_Category

Clinical interpretation of the score (> 100: No Risk, 97.5 - 100: Mild Risk, 83.5 - <97.5: Moderate Risk, < 83.5: Severe Risk).

Arguments

albumin_g_dl

Numeric. Serum Albumin level in g/dL. Note: The formula converts this to g/L internally.

current_weight_kg

Numeric. The patient's current weight in kilograms.

usual_weight_kg

Numeric. The patient's usual or baseline weight in kilograms.

Details

The formula used is: $$NRI = (1.519 \times Albumin_{g/L}) + 41.7 \times \frac{Current Weight}{Usual Weight}$$ Note: If Current Weight exceeds Usual Weight, the weight ratio is set to 1 to avoid overestimating nutritional status in obese patients with hypoalbuminemia.

References

Buzby GP, et al. Prognostic nutritional index in gastrointestinal surgery. Am J Surg. 1980;139(1):160-167. doi:10.1016/0002-9610(80)90246-9 Veterans Affairs Total Parenteral Nutrition Cooperative Study Group. Perioperative total parenteral nutrition in surgical patients. N Engl J Med. 1991;325(8):525-532. doi:10.1056/NEJM199108223250801

Examples

# Example 1: Normal Status
# Albumin 4.5 g/dL (45 g/L), Weight stable (Ratio 1)
# Score = (1.519 * 45) + 41.7 = 68.355 + 41.7 = 110.1
nri_score(4.5, 70, 70)

# Example 2: Severe Risk
# Albumin 2.5 g/dL (25 g/L), Significant weight loss (55/70 = 0.785)
# Score = (1.519 * 25) + (41.7 * 0.785) = 37.975 + 32.73 = 70.7
nri_score(2.5, 55, 70)