UWL: Association With Outcomes (2009)
To investigate the relationship between weight loss and behavioral symptoms in institutionalized Alzheimer's disease subjects.
- Subjects were enrolled from the skilled nursing facilities and assisted living facilities of two retirement communities in Durham, NC
- Otherwise stable patients with a diagnosis of possible or probable Alzheimer's disease according to NINCDS-ADRDA criteria were eligible for the study.
None specifically mentioned.
- 32 residents with probable or possible Alzheimer's disease living in two facilities that included assisted living and nursing care. Potential participants were identified by care providers and review of medical records
- Six subjects were simultaneously participating in a trial on the effect of donepezil.
- Data was analyzed using nonparametric and parametric methods to identify differences between those who lost weight and those who did not lose weight, and to correlate change in neurobehavioral symptoms with change in weight over time
- Wilcoxon rank sums test was used to evaluate differences in descriptive variables between the weight loss and weight gain groups
- The relationship between specific variables such as BMI, weight change and neurobehavioral symptoms in the entire sample were evaluated with the Spearman correlation
- Multivariable analyses were not done due to small sample size
- Caloric intake was averaged due to the fact that 16 participants had less than six days of measurement during the study.
Timing of Measurements
- At enrollment, an evaluation was done by a geriatrician to confirm the diagnosis of possible or probable Alzheimer's disease
- Weight was measured monthly
- At baseline, three months and six months, the Neuropsychiatric Inventory: Nursing Home Version; two-day calorie counts; two-day activity measurement; an interview with a regular caregiver; and a chart review was completed.
- Neurobehavioral symptoms assessed with Neuropsychiatric Inventory: Nursing Home Version
- Eating habits questionnaire was developed by investigators regarding eating habits, food intake and appetite
- Food intake measured through two-day calorie counts
- Physical activity measured with accelerometer.
- Initial N: 32 residents
- Attrition (final N): 32 residents
- Age: Mean age 84.4±7.2 years in weight loss group, 83.9±7.9 years in weight gain group
- Location: Durham, North Carolina.
|Weight Loss Group (N=13)||
Weight Gain Group (N=19)
Weight change over six months
|Gender (% female)||85||95|
|Co-morbidity cumulative illness categories endorsed||5.1±2.4||5.9±1.4|
|Alzheimer disease severity (clinical dementia rating)||2.5±0.8||2.1±0.6|
|Number of medications||4.8±2.2||6.2±1.6|
|Number of psychoactive medications||0.9±0.9||0.7±1.2|
|Functional status, Physical Self-maintenance Scale (six to 30)||15.4±5.5||15.5±4.8|
|Social involvement Multidimensional Observational Scale for elderly subjects (eight to 34)||13.5±5.3||12.1±4.6|
|Caloric intake (kcal per kg)||33.7±10.2||27.9±7.3|
|Behavioral symptoms (Neuropsychiatric Inventory Total at baseline, zero to 144)||20.6±25.3 (zero to 78)||26.7±26.4 (zero to 96)|
At baseline, the mean BMI was 24.0±3.5 with 12 subjects exhibiting a BMI less than 22.
Of the 32 subjects, 13 had lost weight at the end of six months (-4.7±3.6 lbs, range 0.3 to 11.7 lbs) compared with 19 subjects who gained weight (6.3±5.9 lbs, range 0.7 to 19.5 lbs).
BMI was negatively associated with the baseline Neuropsychiatric Inventory total score (Spearman correlation coefficient equaled -0.52, P<0.01), indicating that subjects with low BMIs were more likely to have higher frequency and severity of behavioral problems.
Individual behavior scores for agitation or aggression (-0.40, P<0.05), depression (-0.31, P=0.08), irritability and lability (-0.47, P<0.01), aberrant motor behavior (i.e., pacing, -0.42, P<0.05), nighttime behavior (-0.37, P=0.05), and appetite or eating (-0.48, P<0.01) at baseline were negatively correlated with baseline BMI.
Behaviors not correlated with BMI were delusions, hallucinations, elation, apathy and disinhibition.
Although this was a small sample followed for a relatively short time period, change in specific Neuropsychiatric Inventory scores from baseline to month six were correlated with the change in weight over the six-month period.
Both agitation and aggression (-0.37, P=0.05) and disinhibition (-0.45, P<0.05) showed negative correlation with weight change, which indicates an association between changes in these behaviors and weight loss.
There were no significant differences between those who lost weight (N=13) and those who did not (N=19) on baseline variables, which included age, comorbidity, functional status and Neuropsychiatric Inventory.
However, those who lost weight had a significantly higher BMI at baseline than those who gained weight.
In summary, this study provides preliminary evidence to support an association between low weight and weight loss with specific behavioral symptoms. Certain neurobehavioral symptoms could influence the energy equation by decreasing caloric intake and increasing energy expenditure. Neurobehavioral symptoms such as agitation, pacing, wandering and appetite and eating changes need to be investigated more specifically so that effective nutritional interventions can be designed.
Relatively small sample size and time of observation was relatively short, which did not allow for multivariable statistical analysis. Six subjects were simultaneously participating in another trial. Most caloric intake measurements were not completely made in all participants, resulting in averaging, and certain participants were not cooperative with wearing accelerometers. In addition, many subjects performed activities with other body parts than the waist where the accelerometer was worn. Researchers did not interfere with the nutritional interventions that were already in place.
Quality Criteria Checklist: Primary Research
|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|
|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?||???|
|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?||???|
|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?||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?||???|
|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.)||???|
|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?||No|
|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?||No|
|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?||No|
|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?||No|
|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?||No|
|7.4.||Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?||No|
|7.5.||Was the measurement of effect at an appropriate level of precision?||No|
|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?||No|
|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?||No|
|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)?||No|
|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?||No|
|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|