UWL: Screening and Assessment Methods (2009)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To assess the effect of nutritional status on the risk of institutional placement in an elderly population of 318 patients with Alzheimer's disease.

Inclusion Criteria:
  • All Alzheimer's disease patients living in a region of Southern France who had been followed by ELSA (Etude Longitudinal de Suivi d'Alzheimer) for at least one year
  • ELSA is a longitudinal study of patients with a diagnosis of Alzheimer's disease according to NINCDS-ADRDA criteria
  • All subjects in the study who had been followed for at least one year and were living in their own homes at the start of the study were included in the analysis.
Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

Participants of ELSA, a longitudinal study of patients with a diagnosis of Alzheimer's disease according to NINCDS-ADRDA criteria. Patients were all living at home at the start of the study and were recruited from the outpatient service of a hospital unit specializing in Alzheimer's disease.

Design

Cohort study. 

Statistical Analysis

  • The relationship between certain baseline patient characteristics and institutional placement was analyzed
  • Bivariate analysis was performed with comparison of means for quantitative variables (by ANOVA) and comparison of frequency distributions for qualitative variables (using the Chi-squared test or Fisher's exact test)
  • Certain quantitative variables such as BMI were transformed to have a normal distribution
  • Two multivariate analyses were performed and a logistic regression with institutional placement as the dependent variable
  • The first analysis only included nutritional independent variables
  • For the final model, other patient-specific variables were added in a stepwise analysis
  • The validity of the model was assessed using the Hosmer and Lemeshow test.
Data Collection Summary:

Timing of Measurements

  • Patients have a comprehensive objective six-monthly assessment to evaluate various cognitive and non-cognitive parameters
  • Data describing patient characteristics were collected at the initial visit
  • Data from the first two follow-up visits (at six and 12 months) were analyzed regarding institutional placement.

Dependent Variables

Institutional placement defined as sheltered housing and moving in with a care family

Independent Variables

  • Nutritional status assessed with Mini Nutritional Assessment, BMI and serum albumin
  • Physical incapacity measured using Katz Activities of Daily Living Scale
  • Cognitive function evaluated using Folstein's Mini-Mental Status Examination
  • Behavioral problems assessed with Cohen-Mansfield scale
  • Mood was assessed with Cornell scale for depression in dementia.

Control Variables

  • Age
  • Gender.
Description of Actual Data Sample:
  • Initial N: 384 individuals in initial population
  • Attrition (final N): 318 individuals at one-year follow-up (67.2% women). Follow-up data unavailable for 17.2% (N=66). Most common reasons were due to family members refusal to continue, moving to another town and absenteeism.
  • Age: Mean age at inclusion, 75.4±7 years (range 45 to 89 years)
  • Anthropometrics: Baseline characteristics of those who did not attend the one-year follow-up showed no differences compared with those who remained in the study regarding nutritional parameters or severity of Alzheimer's disease
  • Location: France.
Summary of Results:

Factors Associated With Institutionalization at One Year After Adjustment for Age

Variables

Odds Ratio 95% Confidence Interval

P-value

MNA

2.19 1.00 to 4.77 0.049
Overeating 4.98 1.57 to 15.81 0.006
Pacing 1.99 0.94 to 4.25 0.072
Age 1.06 0.99 to 1.12 0.065

Female gender

0.59

0.27 to 1.27

0.177

Other Findings

  • After one year, 64 of 318 (20.1%) of the patients had moved into institutional care while 254 remained at home
  • 38.7% (N=122) of the patients had family history of Alzheimer's disease, while in 12.4% (N=39) of patients, family history was uncertain
  • The mean Mini-Mental Status Examination score was 17.4±5.9, with 84.5% of the subjects having a score less than or equal to 23
  • Mean Mini Nutritional Assessment score was 24.9±2.5 with only two subjects having a score under 17, consistent with protein-energy malnutrition
  • 19% (N=49) had scores between 17 and 23.5 and therefore at were risk for malnutrition
  • Mean BMI was 24.4±3.8, with 10.3% of subjects having a BMI less than or equal to 20
  • Mean serum albumin was 43.5±4.5
  • Only 12.4% of patients needed any help to feed themselves, of whom most only needed partial help, but 30.4% needed accompaniment for shopping and 24.9% were completely unable to do their shopping
  • Carers reported eating behavioral problems in 11.9% of subjects, divided into a tendency to overeat (7.1%), anorexia (4.8%) and risk of ingesting toxic substances (1.9%)
  • 21.2% of cases in the low MNA group and 10% of cases in the high MNA group were institutionalized at one year (P=0.015)
  • Multivariate analysis showed that a Mini Nutritional Assessment score (MNA) of less than 25.5 (median score of the sample) and overeating behavioral problems (P=0.006) were risk factors for institutional placement. 
Author Conclusion:

This study shows that the risk of placement in an institution in the short term for Alzheimer's disease sufferers, is related to nutritional status, as measured by the Mini Nutritional Assessment. Nutritional problems are reversible and patients with a low MNA score could benefit form a thorough geriatric assessment, in order to slow or prevent institutional placement.

Funding Source:
Other: not described
Reviewer Comments:

Authors note that this study does not give a precise definition of malnutrition, as well as the fact that the strength of the MNA is that it comprises elements relating to the elderly person's lifestyle as well as objective clinical parameters.

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? 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? 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.) 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? 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? 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? Yes
  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? 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? 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? 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