### Description

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.