Index of Undernutrition

 

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.