Unintended Weight Loss in Older Adults

UWL: Association With Outcomes (2009)

Citation:

Kagansky N, Berner Y, Koren-Morag N, Perelman L, Knobler H, Levy S. Poor nutritional habits are predictors of poor outcome in very old hospitalized patients. Am J Clin Nutr. 2005; 82: 784-791.

PubMed ID: 16210707
 
Study Design:
Prospective Cohort Study
Class:
B - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To identify risk factors for development of malnutrition in very old hospitalized patients and to evaluate the total Mini Nutritional Assessment score and subscores as predictors of in-hospital and long-term mortality.

Inclusion Criteria:

Patients 75 years of age or older in a geriatric hospital.

Exclusion Criteria:
  • Severe cognitive impairment that interfered with MNA administration (N=52)
  • Severe hearing loss (N=20)
  • Speech disturbances (N=3)
  • Patients with no particular complaint (N=31).
Description of Study Protocol:

Recruitment

Patients were admitted to the 352-bed geriatric unit within a community hospital, Kaplan-Harzfeld Medical Center. Patients' charts and laboratory data have been computerized since 1997. 

Design

Prospective cohort study. 

Statistical Analysis

  • Differences in nutritional status were analyzed by ANOVA for continuous variables and by the chi-square test for categorical variables
  • Pearson correlation coefficients were calculated for linear relations between total MNA scores or MNA subscores and the laboratory measures
  • MNA subscores were analyzed by Student's T-tests for continuous variables and by the chi-square test for categorical variables
  • Multivariate analyses with forward logistic regression were used to estimate the probabilities of malnutrition and death
  • Odds ratios and their 95% confidence intervals were computed for all variables in the model
  • Patients' total MNA scores were classified into three groups and compared by assessment of survival curves
  • The model's goodness of fit was assessed by the Hosmer-Lemeshow test
  • Receiver operating characteristic curves were created for the models.
Data Collection Summary:

Timing of Measurements

Assessment included demographic; clinical and laboratory data; and cognitive, functional, and nutritional status. All the basic data was collected within three days of admission. Follow-up was conducted for less than 2.7 years.

Dependent Variables

  • Malnutrition
  • In-hospital and long-term mortality
  • Laboratory data: Blood samples were examined for total blood count, renal function, thyroid function, vitamin B12 concentration, transferrin, cholesterol, triacylglycerol, electrolytes, albumin and C-reactive protein.

Independent Variables

Nutritional status was assessed with the Mini Nutritional Assessment and short-form Mini Nutritional Assessment. 

 

Description of Actual Data Sample:
  • Initial N: 520 patients admitted to the geriatric ward
  • Attrition (final N): 414 patients were included in the study, 65.7% females
  • Age: Mean age, 84.8±6.1 years (range 75 to 103 years)
  • Location: Israel.
Summary of Results:

Risk Factors for Malnutrition (MNA Score Less than 23.4)

Variables

OR (95% CI)

P-value

Albumin

4.76 (2.56, 9.09) <0.001

Dementia

3.85 (1.55, 9.59)

0.004

CVA 3.73 (1.54, 8.99) 0.003
Phosphorus 1.49 (1.07, 2.04) 0.017

Other Findings

  • Of the 414 patients studied, 73 (17.6%) were well-nourished, 137 (33.2%) were at risk of malnutrition, and 204 (49.4%) were malnourished
  • 69.3% reported moderate to severe loss of appetite, and 16.7% reported a loss in weight of more than 3.0kg during the previous three months
  • Mean BMI was 23.6±4.5kg/m2 (range 10.5 to 38.8) and the mean MNA score was 17.4±5.6 (range 4.5 to 28.0)
  • Low serum albumin and phosphorus concentrations, dementia and cerebrovascular accident were significant risk factors for malnutrition
  • Survival was significantly lower in malnourished patients and patients at risk of malnutrition than in well-nourished patients (P<0.0001)
  • Low MNA-3 subscores (dietary habits) were significantly correlated with laboratory indexes of malnutrition and were significantly lower in patients with infections, malignancy, pressure ulcers, dementia, recent orthopedic surgery and cerebrovascular accident
  • Multivariate analysis showed that a low MNA-3 score was an independent predictor of mortality; scores less than 7.5 increased the risk of death 2.05-fold. 
Author Conclusion:

In summary, the results of the present study show a high prevalence of malnutrition in very old hospitalized patients. Malnutrition, or even risk of malnutrition, as defined by low MNA scores, was a predictor of long hospital stay and high mortality. The MNA-3 subscore (questionnaire on dietary habits) was significantly correlated with the total MNA score and with laboratory indexes of malnutrition and was also significantly low in patients with the most coexisting medical conditions. Moreover, this subscore was a significant predictor of hospitalization outcome and long-term mortality. Screening for dietary habits is a quick and easy tool for nutritional assessment. We suggest that this is the most important component of screening for malnutrition, and that the MNA-3 might be a useful tool in planning programs of preventive nutrition in frail, very old patients.

Funding Source:
Other: Not reported
Reviewer Comments:

31 patients were excluded "for no particular complaint" (6% of original population). Nutritional status was assessed only at admission, does not address any nutritional interventions that may have affected nutritional status over the follow-up period in the geriatric hospital. Authors note the following limitations:

  • The usefulness of the MNA in the very old is sometimes limited as a result of the anxiety, depression and decline in cognitive functions that are common in this age group
  • Possibility that the multiple comorbidities and treatment regimens of the patients might have influenced their outcome
  • Results obtained in this population of very old patients might not apply to younger patients.
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) N/A
  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) N/A
 
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? ???
  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? N/A
  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? ???
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  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? Yes
  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? ???
  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%.) ???
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? ???
  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? ???
  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? No
  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? No
  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? ???
  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? ???
  7.5. Was the measurement of effect at an appropriate level of precision? ???
  7.6. Were other factors accounted for (measured) that could affect outcomes? ???
  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)? Yes
  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? No
  10.2. Was the study free from apparent conflict of interest? Yes