The index of Undernutrition uses anthropometric and serum protein measurements to assess patients for protein-calorie undernutrition. It can be used to monitor patients over time.
Measurements:
(1) serum albumin (conventional mg/dL; SIU g/L; mg/dL * 0.01 = g/L)
(2) transferrin (conventional mg/dL; SIU g/L; mg/dL * 0.01 = g/L)
(3) per cent weight loss
(4) per cent mid-arm muscle area (MAMA) vs 50th percentile of normal population
(5) per cent mid-arm fat area (MAFA) vs 50th percentile of normal population
Parameter |
Finding |
Points |
albumin |
< 2.0 |
20 |
|
2.0 - 2.5 |
15 |
|
2.6 - 3.0 |
10 |
|
3.1 - 3.5 |
5 |
|
> 3.5 |
0 |
transferrin |
< 100 |
20 |
|
100 - 140 |
15 |
|
141 - 175 |
10 |
|
176 - 200 |
5 |
|
> 200 |
0 |
percent weight loss |
> 20% |
20 |
|
15 - 20% |
15 |
|
11 - 14% |
10 |
|
1 - 10% |
5 |
|
0% |
0 |
percent MAMA |
< 40% |
20 |
|
40 – 60% |
15 |
|
61 – 75% |
10 |
|
76 – 80% |
5 |
|
> 80% |
0 |
percent MAFA |
< 30% |
20 |
|
30 – 45% |
15 |
|
46 – 55% |
10 |
|
56 – 70% |
5 |
|
> 70% |
0 |
total score =
= SUM(points for all 5 parameters)
Interpretation:
• minimum score 0 points
• maximum score 100 points
• The higher the score, the more likely the patient is undernourished.
• Patients with high scores tend to be older, have more adverse clinical events and have longer hospitalizations.
Implementation Notes:
• The 50%th percentiles for mid-arm muscle area and fat area are from Frisancho.
• While Hall uses Heymsfield's correction for mid-arm muscle area (see above), Heymsfield's equation applies only to persons 20-70 years of age; by opting to not use the correction factor, things are much simpler to calculate. The small degree of error is felt to be acceptable since: (a) the scoring is based on a range of percentages, (b) trends in scores are probably more important than a single score.
• The equation for mid-arm muscle area is: ((((10 * (mid-arm circumference in cms)) - (( π) * (triceps skinfold in mm)) ^ 2) / ( 4 * (π)), as derived previously.
• The equation for mid-arm arm fat area is: (5 * (upper arm circumference in cms) * (triceps skinfold in mm)) - (((π)^2) * ((triceps skinfold in mm)^2) / (4 * (π))), as derived previously.
Specialty: Nutrition
ICD-10: ,