UWL: Screening and Assessment Methods (2009)

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

To examine food intake patterns and how they change in relation to BMI, behavioral function and cognitive status in institutionalized seniors with Alzheimer's disease.

Inclusion Criteria:
  • Subjects with likely Alzheimer's disease
  • Residing at home for the aged
  • Maintained ability to self-feed or required only minimal assistance.
Exclusion Criteria:
  • Diagnosis of cognitive impairment secondary to other causes such as vascular dementia or other neurodegenerative disorders
  • Absence of other diseases requiring nutritional intervention, such as diabetes.
Description of Study Protocol:

Recruitment

All residents of the Cognitive Impairment units of the Jewish Home for the Aged at the Baycrest Centre for Geriatric Care were considered.

Design

Time series study. 

Statistical Analysis

  • Meal-related nutrient intakes and delivery, as well as within-individual variability, expressed as standard deviation and coefficient of variation, were compared using repeated measures ANOVA, followed by Tukey's Honestly Significant Difference test
  • Data examined for normality prior to analyses using the Shapiro-Wilk statistic
  • Estimation of the prevalence of inadequate protein intakes was performed by probability analysis
  • Regression analyses used to determine the associations between cognitive status, behavioral function, BMI, mean energy intake of the individual and mean percentage of contribution of each meal to the total energy intake.
Data Collection Summary:

Timing of Measurements

21 consecutive days of food intake collections.

Dependent Variables

  • Food intake weighed by investigator and nutrient profile determined using nutritional software 
  • Behavioral function measured by London Psychogeriatric Rating Scale
  • Cognitive status determined using Mini-Mental State Examination.

Independent Variables

Presence of Alzheimer's disease.

 

Description of Actual Data Sample:
  • Initial N: 25 subjects (three men and 22 women) 
  • Attrition (final N): 25
  • Age: Mean age, 85.9±7.6 years
  • Other relevant demographics: 48% had a BMI less than 22, and 23 of 25 subjects were severely cognitively impaired
  • Location: Canada.
Summary of Results:

Group Mean Energy Delivered Based on 21-day Means for 25 Individuals

Meal Mean Energy (kcal±SD) Range (kcal)

Mean Within-Individual (SD±SD)

Mean Within-Individual (CV±SD)

Breakfast

643±193
P<0.05
415 to 1,031
89.6±42.0
P<0.05
14.2±5.8
P<0.05
Lunch
724±121
P<0.05
527 to 1,068
183.0±67.8
P<0.05
25.0±7.3
P<0.05

Dinner

729±112
P<0.05
575 to 1,103
189.7±46.0
P<0.05
26.0±4.7
P<0.05
Meal Total
2,097±364
1,571 to 3,196
262.5±67.2
12.6±2.9

Other Findings

  • 88% of participants did not meet targeted energy needs, including an estimated 37% prevalence of protein inadequacy
  • Subjects with increased behavioral difficulties had reduced meal-related intakes that were highly associated with decreased energy consumption at dinner
  • With behavioral changes, particularly increased mental disorganization and confusion, there was a shift in circadian eating patterns such that the greatest proportion of daily energy was consumed at breakfast
  • Individuals with low BMIs tended to be those with more behavioral difficulties, such that BMI was also associated with the shift in overall eating patterns
  • Those with low BMIs consumed a greater percentage of the day's total energy at breakfast and less at lunch and dinner and also tended to consume a higher percentage of energy as snacks.
Author Conclusion:
  • In summary, this study provides the most extensive measures of food intake in a population of institutionalized seniors with Alzheimer's disease to date
  • Collectively, thIs data suggests that poor food intake, which associates with increased behavioral difficulties (possibly related to sundowning), likely contributes to poor BMI
  • Consistent with a disturbance in circadian rhythms, peak food consumption levels shift from evening to morning in those with decreased behavioral function
  • Importantly, this suggests that with behavioral changes and Alzheimer's disease progression the provision of high energy, nutrient-dense afternoon and evening meals is unlikely to meet the nutritional needs of this population and that consideration must also be given to changes in meal-time assistance needs throughout the day.
Funding Source:
Reviewer Comments:
  • Small number of subjects from one nursing home
  • Authors note that while behavioral function is important, it is unlikely the sole contributor to the eating patterns observed; diminished hunger and satiety signals may not be sufficient to drive individuals to increase breakfast intake to compensate for reduced dinner intake
  • Some participants may have required increased feeding assistance to meet nutritional needs.
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? 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? 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? No
  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? ???
  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)? ???
  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