Unintended Weight Loss in Older Adults

UWL: Screening and Assessment Methods (2009)

Citation:

Formiga F, Chivite D, Mascaro J, Ramon JP, Pujol R. No correlation between Mini Nutritional Assessment (short form) scale and clinical outcomes in 73 elderly patients admitted for hip fracture. Aging Clin Exp Res. 2005; 17: 343-346.

PubMed ID: 16285202
 
Study Design:
Prospective Cohort Study
Class:
B - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
  • To assess whether concordance between MNA-SF scores and biological nutrition parameters also exists among a cohort of elderly patients suffering from a severe injury such as hip fracture
  • To evaluate the ability of MNA-SF scores to detect higher in-hospital mortality, nosocomial infection or new pressure ulcer occurrence
Inclusion Criteria:
  • Patients more than 64 years of age admitted for osteoporotic hip fracture following minor trauma to a 1,000-bed teaching hospital between January 2002 and March 2002
  • All fractures had to be radiographically confirmed and considered suitable for surgical repair.
Exclusion Criteria:
  • Patients who received conservative therapy (N=2)
  • Those with pathological fractures (N=2) or multiple fractures (N=7)
  • Terminally ill patients with a presumed life expectancy of less than six months (N=5)
  • Those for whom surgery was delayed for 48 hours or more (N=6)
  • Those who were taking lipid-lowering drugs (N=5). 
Description of Study Protocol:

Recruitment

100 consecutive elderly people who were admitted for hip fracture and who underwent surgery complemented by rehabilitation therapy.

Design

Prospective cohort study. 

Intervention

  • MNA-SF nutritional scale and laboratory values were assessed within three days after hip fracture surgery
  • According to hospital guidelines, all patients received antibiotic and antithrombotic prophylaxis, and protein supplements (20g per day)
  • Spinal anesthesia was used
  • Patients were mobilized early and rehabilitation was started as soon as possible.

Statistical Analysis

  • Chi-square and Student's T-test were applied
  • Pearson correlation coefficients were calculated
  • All statistical test were two-sided.
Data Collection Summary:

Timing of Measurements

MNA-SF nutritional scale and laboratory values were assessed within three days after hip fracture surgery.

Dependent Variables

  • Weight, height and BMI
  • Serum albumin, cholesterol and total lymphocyte count
  • Functional status assessed by Barthel Index
  • Comorbidity measured by Charlson score
  • Complications arising from hospital stay (nosocomial infection and pressure ulcers) were recorded.

Independent Variables

  • Nutritional status measured with MNA-SF nutritional scale, consisting of six items extracted from MNA: BMI, appetite, weight loss, mobility, current illness and neuropsychological problems 
  • Interviewed about their prior residential status (nursing home or community), social status and ability to perform activities of daily living.

 

Description of Actual Data Sample:
  • Initial N: 100 consecutive patients. 73 remained after application of exclusion criteria.
  • Attrition (final N): 73 patients [61 female (84%), 12 male]
  • Age: Mean age 81.5±7.1 years
  • Location: Spain.
Summary of Results:

 

Variables

Values MNA-SF Pearson Correlation Coefficients

P-Value

Serum total cholesterol (mmol per L)

4.35±1.1 R=0.099 0.4

Serum albumin (g per L)

30.6±3.6

R=0.082

0.4

Serum total lymphocytes per mm3 1,278±463 R=0.147 0.2
Previous Barthel Index 78.2±19 R=-0.59 0.6
Charlson Score 1.6±0.3 R=0.31 0.7

Other Findings

  • Inhospital mortality was 10%. MNA-SF scores of these patients pointed toward a higher risk of malnutrition (8.8 vs. 10.1) but this difference did not reach statistical significance.
  • The mean MNA-SF score was 11±0.5 (range, three to 14); according to these values, 39 patients (53%) were at risk of malnutrition
  • MNA-SF scores were not significantly correlated to patients' laboratory values
  • Seven (9.5%) patients with normal MNA-SF scores had albumin levels less than 30g per L
  • MNA-SF values did not correlate either with previous functional status or with comorbidity
  • 14 episodes of nosocomial infection were diagnosed in 11 patients, and six patients developed pressure ulcers during hospitalization. The MNA-SF values were not useful in predicting the development of nosocomial infection (P=0.3) or those at risk for pressure ulcers (P=0.2). 
Author Conclusion:

MNA-SF test scale values reflect a clinical process in post-operative hip-fractured patients that is different from serum albumin, cholesterol or lymphocyte count. In conclusion, we believe that the MNA-SF and the biochemical nutrition values applied reflect different clinical processes.

Funding Source:
University/Hospital: Hospital Universitari de Bellvitge
Reviewer Comments:

Authors note that the MNA-SF questionnaire is the first of a two-step process, that if the MNA-SF is negative, there is no need to answer the remaining MNA questions. Authors note the following:

  • Lack of predictive value may be attributed to the following: A low MNA-SF score does not represent a risk to those patients in whom hypoalbuminemia is not present, provided that they are correctly managed with good medical care
  • Two possible limitations: Short duration of follow-up and small sample size.
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? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  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%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  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? Yes
  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.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? Yes
  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? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  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? Yes
  6.6. Were extra or unplanned treatments described? Yes
  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? Yes
  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? Yes
  7.7. Were the measurements conducted consistently across groups? N/A
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)? N/A
  8.6. Was clinical significance as well as statistical significance reported? Yes
  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