Validation of Subjective Global Assessment (SGA) in assessing malnutrition among surgical patients upon

hospital admission at Hospital Tuanku Jaafar,

Seremban.

Chong Li Chin Dept of Nutrition & Dietetics, IMU Bukit Jalil, Kuala Lumpur

Malnutrition in Hospital

50 – 55% of patients have low calorie intake, low BMI and MAMC.

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Tai ML, Goh KL, Siti Hawa MT, Sanjay R, Sanjiv M. Anthropometric, biochemical and clinical assessment of malnutrition in Malaysian patients with advanced cirrhosis. Mal J Nutr 2010;9:27 Sakinah H, Suzana S, Noor Aini MY, et al. The magnitude of malnutrition among hospitalized elderly patients in University Malaya Medical Centre.Health and the Envitonmental Journal,2010;1(2): 64-72

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Malnutrition: Causes and consequences

Increased requirements

Loss of ability to eat

Poor nutrient absorption

Malnutrition

Deficiency in dietary intake

Nutrient losses

Loss of appetite

Weight loss

Low energy

Reduced independence

Infections

Confusion

Increased morbidity and mortality

Increased risk of hospital admissions

Muscle wasting

Nutrition Screening

Nutrition screening is important to identify patients at risk of malnutrition.

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Available tools:

NRS 2002

MST

MUST

SGA

Research objective

To validate the use of Subjective Global Assessment (SGA) (Detsky et al. 1987) in detecting malnutrition amongst surgical patients upon admission.

Validation by comparison with objective measurements of

anthropometric

biochemical

Data collection & analysis

INTERVIEW

MEDICAL RECORDS

ANTHROPOMETRIC MEASUREMENTS

i. SES Questionnaire ii. Assessment tool: SGA iii. Diet intake within a week prior to admission

i. Biochemical profile

i. Height and weight ii. Body mass index (BMI) iii. Triceps skinfold (TSF) iv. Mid arm circumference (MAC) v. Corrected mid arm muscle area (cAMA)

STATISTICAL ANAYLISIS i. Sensitivity, specificity and PPV, NPV of each

screening tool

PATIENTS WITHIN 72 HOURS OF

ADMISSION

Validation of SGA tools

Sensitivity % of malnourished patients correctly identified

% of healthy individuals correctly not identified as malnourished

Specificity

Probability of patients with positive test are correctly diagnosed as malnourished

PPV

Probability of patients with negative test are correctly diagnosed as non-malnourished

NPV

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RESULTS

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Male Female p value

n=43 n=62

Weight (kg) 65.1 ± 15.2 58.8 ± 14.3 0.033

Height (cm) 164.9 ± 8.0 156.9 ± 6.3 0.000

BMI (kg/m2) 24.0 ± 5.0 24.0 ± 5.5 0.992

MAC (cm) 29.1 ± 5.4 27.3 ± 5.2 0.087

TSF (mm) 14.6 ± 6.4 20.6 ± 9.7 0.001

cAMA (cm2) 37.1 ± 16.8 29.2 ± 11.9 0.006

Baseline Characteristics

n=11 n=19

Sr. Albumin (g/L) 28.6±6.6 28.3 ±6.9 0.899

SGA score

B and C (Malnourished)

BMI <18.5 kg/m2 (n=105)

Sensitivity (%) 100

Specificity (%) 49

Positive predictive value 0.3

Negative predictive value 1.0

Validation of SGA against BMI

SGA score

B and C (Malnourished)

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MAC ≤ 15th percentile (n=105)

Sensitivity (%) 100

Specificity (%) 47

Positive predictive value 0.2

Negative predictive value 1.0

TSF ≤ 15th percentile (n=105)

Sensitivity (%) 100

Specificity (%) 52

Positive predictive value 0.3

Negative predictive value 1.0

Validation of SGA against MAC and TSF

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SGA score

B and C (Malnourished)

cAMA ≤ 15th percentile (n=105)

Sensitivity (%) 65

Specificity (%) 48

Positive predictive value (%) 0.5

Negative predictive value (%) 0.6

Albumin <35 g/L (n=30)

Sensitivity (%) 64

Specificity (%) 100

Positive predictive value 1

Negative predictive value 0.2

C

Validation of SGA against cAMA and Serum Alb

C

0

10

20

30

40

50

60

70

All, n=105 Male, n=43 Female, n=62

41.9

51.2

35.5

58.1 48.8

64.5

Pe

rce

nta

ge (

%)

Patients

Well- nourished

Malnourished

Malnutrition Rate

Conclusion

SGA showed a high sensitivity when compared against objective anthropometry measurements. SGA showed good specificity compared against serum albumin.

SGA is a valid tool for malnutrition screening amongst surgical patients in Hospital Tuanku Jaafar

Acknowledgement

International Medical University for funding

Prof Winnie Chee, Thesis Supervisor, IMU

Pn Basmawati Bt Baharom, Hospital Tuanku Jaafar

Pn Amirozlin Bt. Amsar, Hospital Tuanku Jaafar

Ms. Chee Li Jiun, 4th year student, IMU

Ms. Lee Li Ting, 4th year student, IMU

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