Unintended Weight Loss in Older Adults

UWL: Nutritional Status (2009)

Citation:

Zuliani G, Romagnoni F, Soattin L, Leoci V, Volpato S, Fellin R. Predictors of two-year mortality in older nursing home residents. The IRA study. Aging Clin Exp Res. 2001; 13: 3-7.

PubMed ID: 11292149
 
Study Design:
Longitudinal study.
Class:
C - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To investigate the possible association of a large number of parameters, including functional, anthropometric, nutritional, metabolic, clinical and demographic variables, with two-year total mortality in a sample of established older nursing home residents.

Inclusion Criteria:
  • Age more than 65 years
  • Residence in the nursing home for at least two months
  • No clinical evidence of acute illness at the time of observation, nor in the previous 30 days. 
Exclusion Criteria:

Terminal patients with cancer or severe liver and kidney disease were excluded.

Description of Study Protocol:

Recruitment

The Istituto di Riposo per Anziani (IRA) study is a longitudinal study designed to evaluate the relationship between a large number of biological parameters, future disability and mortality, in a sample of older nursing home residents. 344 subjects were recruited in 1990 from the 410 residents of the IRA nursing home.

Design

Longitudinal study. 

Statistical Analysis

  • Mean values were compared by unpaired Student's T-test, prevalence by the chi-square test
  • Two-year survival function was estimated by the Kaplan-Meier method
  • The Wilcoxon test and Log Rank test were used to test differences between curves
  • Forward stepwise multivariate logistic regression analyses were used to identify the variables associated with mortality.
Data Collection Summary:

Timing of Measurements

Future disability and mortality assessed after two years.

Dependent Variables

Disability and mortality.

Independent Variables

  • Anthropometric parameters: Weight, height, tricipital and subscapular skinfold thickness, and waist-to-hip circumference were measured by the same physician according to standardized methods; body water, resistance and reactance were determined by tetrapolar bioelectric impedance analysis
  • Clinical chemistry parameters: Fasting blood samples analyzed for serum total protein, iron, albumin, transferrin, blood cell count, total cholesterol, triglycerides, HDL-cholesterol, apo A-I, apo B, LDL-cholesterol, plasma glucose, uric acid, TSH, T3 and T4
  • Health and functional status: Age, gender, number of chronic medical conditions, currently used drugs
  • ADL evaluated through the Katz index.

 

 

Description of Actual Data Sample:
  • Initial N: 344 subjects (272 females, 72 males)
  • Attrition (final N): 216 survived at two years, 128 were deceased
  • Age: Mean 81.1±7.2 in the survivors, mean 83.8±7.0 in the deceased
  • Location: Italy.
Summary of Results:

 

Variables

Two-year Survivors (N=216) Deceased at Two Years (N=128)

Statistical Significance 

Number of pathologies

3.4±1.0 3.8±1.5

0.01

Age (years) 81.1±7.2 83.8±7.0 0.001
Diastolic blood pressure (mm Hg) 86.5±11.4 83.5±10.9 0.01
BMI 24.6±4.5 23.1±4.6 0.02
Tricipital skinfold thickness (mm) 15.3±6.1 13.0±5.6 0.001
Subscapular skinfold thickness (mm) 13.2±5.4 10.9±4.3 0.001
Waist-to-hip ratio 0.92±0.08 0.90±0.07 0.04
Body resistance (ohms)  586.5±96.5 619.3±117 0.01
Body water (L) 55.9±7.7 53.6±6.9 0.03
HDL-cholesterol (mg per dL) 45.6±12.6 42.3±12.2 0.01
T3 (ng per dL) 100.4±25.7 92.0±25 0.003
Hemoglobin (g per dL) 13.1±1.4 12.4±1.5  0.001
Red blood cells (x106 per mmc) 4.4±0.6 4.29±0.49 0.02
Hematocrit (percentage) 39.6±4.3 37.6±4.3 0.001
White blood cells (x1000 per mmc) 6.41±1.7 6.87±2.3 0.03
Serum iron (mcg per dL) 71.0±24.2 63.1±25 0.004

Albumin (g per dL)

4.25±0.36

4.05±0.38

0.001

Other Findings

  • Although a number of factors were associated with mortality risk, multivariate analysis showed that only severe disability (six vs. zero to one lost ADL, odds ratio = 3.37, 95% confidence interval, 1.76 to 7.3) and low albumin levels (lowest vs. highest tertile: Odds ratio = 3.0, 95% confidence interval, 1.65 to 5.43) were independent predictors of outcome
  • Moreover, in the analysis stratified for degree of disability and albumin tertiles, we found a strong gradient in mortality risk with increasing disability and decreasing albumin levels, further supporting the value of these two simple parameters in identifying frail institutionalized older individuals.

 

Author Conclusion:

Among a large number of variables, we found that disability in ADL and low albumin levels were associated with two-year mortality in a sample of established nursing home residents. A simple approach based on the evaluation of these two mortality-related factors should help physicians focus the treatment of high-risk subjects. Interventional studies aimed at a possible reduction in mortality rates through improvements in the functional and nutritional status of these subjects are needed.

Funding Source:
Other: Not reported
Reviewer Comments:

Recruitment methods were not described. All subjects were from the same nursing home. Measurement of mortality was not described. Authors note the following limitations:

  • Comorbidity was defined as the total number of chronic medical conditions; however, the type and severity of disease would also have added important information
  • Standard evaluation of cognitive and affective status was not performed, and both cognitive impairment and depression have been associated with mortality rate in older persons.
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? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? N/A
  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? 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? 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? 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