Unintended Weight Loss in Older Adults

UWL: Association With Outcomes (2009)

Citation:

Thomas DR, Zdrowski CD, Wilson MM, Conright KC, Lewis C, Tariq S, Morley JE. Malnutrition in subacute-care. Am J Clin Nutr. 2002; 75: 308-313.

PubMed ID: 11815323
 
Study Design:
Case Study or Case Series
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To examine the prevalence of undernutrition in a subacute-care facility.

Inclusion Criteria:
  • Consecutively admitted patients to a 100-bed subacute-care center over 14 months
  • Subjects were generally referred from area acute-care hospitals
  • Most patients were admitted for rehabilitation. The most common reasons for admission included orthopedic or neurologic rehabilitation, acute and chronic wounds or infections requiring antibiotic therapy.
  • Admissions from nursing homes, admissions from the subjects' own homes, and acute-care hospital transfers were included in the data collection.
Exclusion Criteria:
  • Subjects re-admitted to the subacute-care facility
  • Subjects with cancer, end-stage renal disease, or terminal illness defined by a do-not-resuscitate status
  • Subjects already receiving artificial enteral or parenteral nutrition.
Description of Study Protocol:

Recruitment

837 consecutively admitted patients to a 100-bed subacute-care center over 14 months. Subjects were generally referred from area acute-care hospitals.

Design

Case Series

Blinding used (if applicable)

Intervention (if applicable)

Statistical Analysis

  • Simple descriptive statistics were used for demographic analysis
  • Student's T-test was used to compare the means of two independent groups
  • Odds ratios were calculated from contingency tables
  • The method of chi-square was used to compare categorical variables
  • ANOVA was used to compare groups of more than three and was followed by a post-hoc test when significantly different
  • Only nine subjects had an MNA score in the well-nourished range; this group was excluded from further analysis.
Data Collection Summary:

Timing of Measurements

Patients consecutively admitted over 14 months. MNA completed at time of admission. Laboratory data collected within 10 days of or on admission.

Dependent Variables

  • Length of stay
  • Death
  • Re-admission to an acute-care hospital
  • Placement at discharge.

Independent Variables

  • Anthropometric measurements: Height recorded, weight measured with standing scale, BMI
  • Biochemical markers: Albumin, cholesterol, sodium, serum urea nitrogen and creatinine
  • Mini Nutritional Assessment score
  • Depression evaluated with Geriatric Depression Scale
  • SCALES protocol for evaluating risk of malnutrition in the elderly was used to assess malnutrition.

Control Variables

 

Description of Actual Data Sample:

Initial N

837 consecutively admitted patients, 61% women

Attrition (final N)

Nutritional status evaluated in remaining 489 subjects. BMI calculated in 390 subjects (47%) due to inability to assess accurate height.

Age

Mean age 76±13 years

Ethnicity

Not mentioned

Other relevant demographics

Anthropometrics

Location

St. Louis, Missouri

 

Summary of Results:

 Length of Stay and Discharge Disposition by BMI

Variables BMI Less Than 22 BMI 22-27 BMI More Than 27

Frequency [N (percentage)]

117 (36.4%) 94 (30.5%) 108 (33.0%)

Length of stay (days)

21.2

21.0

23.0

Discharge to nursing home [N (percentage)] 20 (38.5%) 17 (32.7%) 15 (28.8%)
Discharge to home [N (percentage)] 64 (34.8%) 54 (29.3%) 66 (35.9%)
Discharge to acute-care hospital [N (percentage)] 21 (38.9%) 16 (26.4%) 17 (29.9%)
Death 2 (33.3%) 2 (33.3%) 2 (33.3%)

Other Findings

18% of the subjects had a BMI less than 19; BMI averaged 25.6±7.6.

Only 132 subjects reported a history of weight loss.

Average length of stay was 22.4±15.3 days.

Mean serum albumin concentration was low at 32±6.2g/L; with the use of 35g/L as a cutoff, 67% of the subjects had hypoalbuminemia.

Only 8% of the subjects were classified as being well nourished (score greater than 23.5) according to the MNA;  29% of the subjects were malnourished (score less than 17) and 63% were at risk of malnutrition (score 17 to 23.5).

MNA score was highly correlated with BMI.

Thus, more than 91% of subjects admitted to subacute-care were either malnourished or at risk of malnutrition.

The Geriatric Depression Score was higher in malnourished subjects than in nutritionally at-risk subjects (P=0.05).

The SCALE score correlated well with the MNA because both instruments share common variables (r=0.461, P=0.002).

Length of stay differed by 11 days between the malnourished group and the nutritionally at-risk group (P=0.007).

In the MNA-assessed group of largely malnourished subjects, 25% of subjects required re-admission to an acute-care hospital compared with 11% of the well-nourished group (P=0.06).

Mortality was not found to be related to BMI

Subjects with an MNA score less than 17 were six times more likely to be dehydrated than were subjects who had an MNA score of 17 to 23.5.

Author Conclusion:

Malnutrition reaches epidemic proportions in patients admitted to subacute-care facilities. Whether this reflects nutritional neglect in acute-care hospitals or is the result of profound illness is unclear. Nevertheless, strict attention to nutritional status is mandatory in subacute-care settings.

Funding Source:
Other: Not reported
Reviewer Comments:

Nutritional status and BMI not measured in all subjects. Excluded subjects that seemed pertinent to study.

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? ???
  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? 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? N/A
  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? N/A
  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? 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? ???
  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? 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)? 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? ???
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? No
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