Buzby et al first reported the Nutritional Risk Index (NRI) which is used to identify malnourishment in elderly patients admitted to the hospital.
NOTE: There are several variations for the NRI.
Parameters:
(1) serum albumin in g/L
(2) present weight in kilograms
(3) usual weight in kilograms
NRI =
= ((factor 1) * (serum albumin in g/L)) + ((factor 2) * (present weight) / (usual weight))
Factor 1 |
Source |
Comment |
15.9 |
Buzby (1988) |
probably should be 1.59; the results of the assay were probably reported in g/dL |
1.519 |
Friedmann (1997) |
gives Roubenoff as source |
1.489 |
Naber (1997) |
gives Buzby as source |
Factor 2 |
Source |
Comment |
0.417 |
Buzby (1988) |
ratio reported as percent from 0 to 100 (or more); obtained by multiplying by 100% |
0.417 * 100 |
Friedmann (1997) |
similar to Buzby; includes the 100 but refers to ratio as a percent |
41.7 |
Naber (1997) |
uses the ratio of weights without making a percent |
Form used in implementation:
NRI =
= (1.519 * (serum albumin in g/L)) + (41.7 * (current weight in kg) / (usual weight in kg))
Interpretation:
• The higher the index the less likely the patient is malnourished.
NRI |
Malnourishment |
> 100 |
none |
97.5 to 100 |
mild |
83.5 to 97.4 |
moderate |
< 83.5 |
severe |
Limitations:
• While the NRI would work for many elderly patients it seems to be intended to detect a protein malnutrition rather than vitamin deficiency.
Purpose: To evaluate an elderly patient for malnutrition using the Nutritional Risk Index (NRI), originally reported by Buzby et al.
Specialty: Nutrition
Objective: risk factors
ICD-10: E40-E46, E50-E64,