NSCR: Quick and Easy Nutrition Screening Tools: Adult Patients in Acute and Ambulatory Care Settings (2009)

Citation:
 
Study Design:
Class:
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Quality Rating:
Research Purpose:

The purpose of this study was to test the sensitivity and specificity of screening tools [Nutrition Risk Index (NRI), Malnutrition Universal Screening Toll (MUST), and Nutritional Risk Screening tool 2002 (NRS-2002)] compared to nutritional assessment tools [Subjective Global Assessment (SGA)] and to evaluate the association between nutritional risk determined by these screening or assessment tools and length of stay (LOS).

Inclusion Criteria:

All adult patients admitted to the hospital admission center for medical or surgical reasons and subsequently hospitalized were eligible for inclusion. Every tenth patient who met entry criteria was included in the study during a three-month period.

Exclusion Criteria:

Two patients refused to participate. Exclusion criteria were edema, burns, peritoneal- or hemodialysis, rehydration perfusion and major cardiorespiratory resuscitation, because these conditions preclude the use of bioelectrical impedance analysis or the relevance of the measured body weight.

Description of Study Protocol:

Recruitment

All adult patients admitted to the hospital admission center for medical or surgical reasons and subsequently hospitalized were eligible for inclusion. Every tenth patient who met every criteria was included in the study during a three-month period. 

Design

Prospective cohort design. 

Anthropometric Measurements

  • Performed at hospital admission
  • Height measured to the nearest 0.5cm with a stadiometer, and recumbent height was obtained in patients who were unable to stand
  • Weight  measured to the nearest 0.1kg on a chair scale or a hoist with attached weighing device for patients who were bedridden
  • Body mass index (BMI) was calculated as weight (kg) divided by height (m) squared (kg/m2)
  • Fat-free and fat mass were determined by 50-kHz bioelectrical impedance analysis.

Subjective Global Assessment

  • Used as reference method
  • Questionnaire that incorporates the patients' history (weight loss, changes in dietary intake, gastrointestinal symptoms and functional capacity), physical examination (muscle, subcutaneous fat, sacral and ankle edema, ascites) and the clinician's overall judgment of the patient's status (well nourished, suspected malnourished or moderately malnourished and severely malnourished).

Nutritional Risk Indicator (NRI)

  • NRI equal (1.519 x serum albumin, g per L) + (41.7 x present or usual BW)
  • An NRI score of more than 100 indicates that patient has no risk; 97.5 to 100, low risk; 83.5 to 97.5, medium risk; less than or equal to 83.5, high risk
  • Blood samples to determine albumin levels were drawn at the same time as the samples necessary for diagnosis, but before initiation of IV fluids 
  • Cut-off value for albumin measured by immunonephelometry was set at less than 35g per L (normal range 35g to 55g per L). 

Malnutrition Universal Screening Tool (MUST)

  •  Includes three clinical parameters (BMI, weight loss, acute disease)
  •  Rates each parameter as zero, one or two as follows: BMI more than 20kg/m2, zero; 18.5 to 20.0kg/m2, one; less than 18.5kg/m2, two
  • Weight loss: Less than 5%, zero; 5% to 10%, one; more than 10%, two
  • Acute disease: Absent, zero; if present, two 
  • Overall risk of malnutrition: Zero, low risk; one, medium risk; two, high risk.

Nutrition Risk Screening (NRS-2002)

  • Consists of nutritional score, severity of disease score and an age adjustment for patients aged more than 70 years (+1) 
  • Nutritional score: Weight loss more than 5% in three months or food intake below 50% to 75% in preceding week, one; weight loss more than 5% in two months or BMI 18.5kg/m2 to 20.5kg/m2 and impaired general condition or food intake of 25% to 60% in preceding week, two; weight loss more than 5% in one month or more than 15% in three months or BMI less than 18.5kg/m2 and impaired general condition or food intake 0% to 25% in preceding week, three 
  • Severity of disease score: Hip fracture, chronic patients with acute complications, one; major abdominal surgery, stroke, severe pneumonia, hematological malignancies, two; head injury, bone marrow transplantation, intensive care patients with APACHE more than 10, three
  • Final score is the total of the nutritional score, severity of disease score and age adjustment
  • Patients classified as: No risk, zero; low risk, zero to one; medium risk, three to four; and high risk, greater than or equal to five.

Statistical Analysis

  • Results are expressed as mean±standard deviation (±SD) 
  • Simple correlations were determined between nutritional assessment parameters and screening tools, by categorizing nutrition risk (categories: Low risk, zero; medium risk, one; high risk, two). 
  • X2-test was used to compare the differences in the prevalence of nutritional risk
  • Sensitivity, specificity and predictive values were calculated to evaluate the different nutritional screening tools
  • Agreement between the assessment methods was also analyzed by kappa (κ) statistic
  • The value of κ varies from zero to one, a value of less than 0.2, poor; 0.2 to 0.4, fair; 0.4 to 0.6, moderate; 0.6 to 0.8, substantial; more than 0.8, almost perfect concordance
  • Multiple logistic regressions, adjusted for age, were used to estimate odds ratios (OR) for associations between nutritional screening tools and LOS
  • OR with 95% confidence intervals (CIs) describe the magnitude of effects for each level of the study variable compared with the reference category
  • Statistical significance was set at P≤0.05 for all tests.
Data Collection Summary:

Timing of Measurements

All measurements were performed at hospital admission.

 Dependent Variables

  • Variable 1: Nutrition risk (low, medium, high) measured with NRI, MUST, and NRS-2002 nutrition risk screen instruments
  • Variable 2: Sensitivity (measured by comparing results of SGA with NRI, MUST, and NRS-2002 nutrition risk screen instruments)
  • Variable 3: Specificity (measured by comparing results of SGA with NRI, MUST, and NRS-2002 nutrition risk screen instruments)
  • Variable 4: Positive predictive value (measured by comparing results of SGA with NRI, MUST, and NRS-2002 nutrition risk screen instruments)
  • Variable 5: Negative predictive value (measured by comparing results of SGA with NRI, MUST, and NRS-2002 nutrition risk screen instruments).

Independent Variables

Level of nourishment: Well-nourished, suspected malnourished or moderately malnourished, severely malnourished [measured by the Subjective Global Assessment (SGA)]. 

 

 

Description of Actual Data Sample:

Initial N

995.

Age

For patients with a hospital stay of one to 10 days, 50±21.9; patients with a hospital stay more than 11 days, 65.4±18.7; length of stay unknown, 44.4±17.0 (difference is statistically significant between one to 10 days and more than 11 days and more than 11 days and LOS unknown).

Other Relevant Demographics

The proportion of male to female was not significantly different between patients hospitalized one to 10 and more than 11 days (one to 10 days, 420 males, 384 females; more than 11 days, 80 males, 68 females; LOS unknown, 25 males, 18 females) .

Anthropometrics 

LOS
1-10 days
>11 days
LOS Unknown
P
Weight (kg)
67±13.8
64.5±18.7
66.6±16.6
0.135
BMI (kg/m2)
23.9±4.1
23.7±4.5
23.2±5.0
0.532
Weight loss (%)
-1.6±6.3
-3.6±-6.7
-1.0±-6.1
<0.001*
Albumin (g per L)
41.9±5.7
39.0±6.2
 
<0.001*
Fat-free mass (kg)
47.7±10.6
44.8±10.4
47.6±11.1
0.002*
Body fat (%)
28.6±8.9
30.2±8.9
27.7±9.0
0.079

*Significantly different between one to 10 days and more than 11 days. 

Location

Geneva University Hospital, Geneva, Switzerland.

Summary of Results:

 

  •  NRI classified 75% of patients as low, 20% as medium and 5% as high risk
  • SGA classified 56% of patients being well nourished, 33% moderately malnourished and 11% severely 
  • MUST classified 63% of patients as low, 10% as medium and 27% as high risk
  • NRS-2002 classified 72% low, 19% medium and 9% high risk compared to 61% well nourished, 29% moderately malnourished and 10% severely malnourished
  • The NRS-2002 misclassified 26.6%, the MUST 41.5% and NRI 38.6% of patients
  • The sensitivity was 62% with the NRS-2002, 61% with the MUST and 43% with the NRI and specificity was 93%, 76% and 89% with the NRS-2002, MUST, and NRI, respectively
  • NRS-2002 had higher positive (85%) and negative predictive values (79%) than the MUST (65% and 76%, respectively)
  • Agreement was moderate between SGA and NRS-2002 (κ = 0.48, P<0.001), and fair between SGA and NRI (κ = 0.26, P<0.001) and SGA and NRI (κ = 0.24, P<0.001).

 

Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value, and Kappa Statistic: NRI, MUST and NRS-2002 Vs. SGA

 

NRI

 

 

MUST

 

 

NRS-2002

 

Low

Medium/

High

Total

Low

Medium/

High

Total

Low

Medium/

High

Total

 

%

95% CI

 

%

95% CI

 

%

95% CI

 

Sensitivity

43.1

37.3-49.0

 

61.2

56.2-66.1

 

62.0

57.0-66.9

 

Specificity

89.3

85.6-92.3

 

78.6

75.1-81.8

 

93.1

90.8-94.9

 

Positive predictive value

76.2

67.0-82.5

 

64.6

59.5-69.5

 

85.1

80.4-89.1

 

Negative predictive value

66.2

61.9-70.4

 

76.1

72.6-79.4

 

79.4

76.2-82.3

 

κ

 

0.24

 

 

0.26

 

 

0.48

 

CI, confidence interval; κ statistic, percent of agreement.

Author Conclusion:

A large percentage of patients were at medium or high nutritional risk (39% by SGA, 28% by NRS-2002 and 37% by MUST) at hospital admission. NRS-2002 had higher sensitivity and specificity than MUST or NRI, compared to SGA. There was a significant association between LOS and nutritional risk by NRS-2002, MUST and NRI and nutritional status by SGA. Nutritional risk or status can be determined by NRS-2002, MUST and SGA, respectively, in patients at hospital admission.

Funding Source:
Not-for-profit
0
Foundation associated with industry:
Reviewer Comments:
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? ???
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? ???
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? No
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes