UWL: Medical Nutrition Therapy (2007)

Citation:
 
Study Design:
Class:
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Quality Rating:
Research Purpose:

To evaluate the impact of nutritional supplementation on nutritional status, muscle strength, perceived health and functional status in a population of community-living, frail and undernourished elderly people.

Inclusion Criteria:
  • Older than 65 years
  • At high nutritional risk, defined as involuntary weight loss of 5% body weight in the past month, more than 7.5% in the past three months, or more than 10% in the past six months and BMI less than 27, or BMI less than 24
  • Subjects were oriented to time and place as judged by the research assistant.
Exclusion Criteria:
  • Receiving palliative care
  • Alcoholic
  • Had active cancer or an illness requiring a therapeutic diet incompatible with supplementation.
Description of Study Protocol:

Recruitment

Study subjects were recruited from January 1997 to December 1997 from among those receiving long-term home help services (such as housework, personal hygiene or food preparation) offered by seven local community services centers in the area of Sherbrooke, Quebec, Canada.

Design

Randomized controlled trial. Randomization was stratified by sex and nutritional risk criteria.

Blinding Used 

Data were collected by two dietitians. One was responsible for recruitment and collection of baseline and follow-up nutritional data on a bimonthly basis, and one dietitian blinded to treatment assignment completed measurements of functional and health status outcome variables at the start and end of the 16-week intervention.

Intervention

  • Subjects were randomized to an experimental or control group and visited in their home on a monthly basis for 16 weeks 
  • Provision of two nutrient-dense protein-energy liquid supplements per day (Ensure or Ensure Plus, 235-ml cans) and encouragement to improve intake from other foods rather than replace meals with liquid supplement
  • Compliance was measured every month at the time of the home visit by a count of supplements and dietary interview
  • Between visits, subjects were contacted by phone every two weeks and given nutrition counseling and encouragement to improve food and supplement intake
  • Subjects in the control group did not receive any treatment but were visited each month and given a small gift to control for any greater attention.

Statistical Analysis

  • Similarity of baseline characteristics of groups tested using unpaired T-tests or chi-squared tests
  • Study groups were compared on an "intention to treat" basis using ANOVA for repeated measures
  • Paired T-tests were also performed on the means of changes over ther 16-week period
  • Mann-Whitney's and Wilcoxon's tests were used for group and time effects, respectively, in subgroup analyses or where data were not normally distributed
  • A secondary analysis compared compliers with controls to investigate whether a subset of subjects showed improvement, keeping in mind that potential confounders cannot be adequately controlled in this subgroup analysis.
Data Collection Summary:

Timing of Measurements

Outcomes measured at start and after 16 weeks at subjects' homes.

Dependent Variables

  • Height and weight measured with indoor clothing and without shoes using level platform with attached measuring tape and portable scale
  • BMI calculated
  • Triceps, subscapular and suprailiac skinfold thicknesses measured using a Harpenden skin caliper
  • Mid-upper-arm and calf circumferences were measured using flexible, non-stretch fiberglass tape
  • Maximal voluntary handgrip strength measured using vigorimeter 
  • Maximum voluntary isometric elbow flexion and knee extension strength tested using handheld dynamometer 
  • Lower extremity function measured using timed "up and go" test
  • Perceived health and functional status obtained using 36-item Short Form Health Survey (SF-36) 

Independent Variables

  • Subjects were randomized to an experimental or control group and visited in their home on a monthly basis for 16 weeks 
  • Usual baseline dietary intake assessed by three non-consecutive 24-hour recalls (one face-to-face, two by telephone) over two-week period before randomization
  • Repeated 24-hour recalls obtained every two weeks throughout the intervention
  • Dietary data coded by the same dietitian and nutrient analysis carried out using CANDI and the Canadian Nutrient File
  • Provision of two nutrient-dense protein-energy liquid supplements per day (Ensure or Ensure Plus, 235ml cans) and encouragement to improve intake from other foods rather than replace meals with liquid supplement
  • Compliance was measured every month at the time of the home visit by a count of supplements and dietary interview
  • Between visits, subjects were contacted by phone every two weeks and given nutrition counseling and encouragement to improve food and supplement intake
  • Subjects in control group did not receive any treatment but were visited each month and given a small gift to control for any greater attention.

Control Variables

Data collected on sociodemographic characteristics, age, smoking, alcohol consumption, concurrent illness, medication use and living arrangements.

Description of Actual Data Sample:
  • Initial N: 116 subjects met all eligibility criteria. 23% declined to participate, the most frequent reason being the refusal to take an oral nutritional supplement. After providing informed consent, 89 subjects were randomized to the experimental (N=43) or control (N=46) group. 
  • Attrition (final N): 83 elderly people, 42 in experimental group, 41 in control group (in abstract, figure one, table two). 41 in experimental group (12 men, 29 women), 42 in control group (12 men, 30 women) (in table one). Five refused the assignment (one from the treatment group and four from the control group) and one subject in the experimental group was lost to follow-up due to cancer diagnosis.
  • Age: Mean age, 80±7 years. Mean age, 81.6±7.5 years in experimental group, 78.6±6.1 years in control group
  • Other relevant demographics: Mean weight 53.7±8.6kg in experimental group, 52.9±9.3kg in control group. Mean BMI 20.1 in both groups
  • Anthropometrics: Groups were significantly different at baseline in age (P<0.049)
  • Location: Canada.
Summary of Results:

Energy and Protein Intake, Weight Gain, and Changes in Anthropometric Indices and SF-36 Health Status Subscales

Variables

Control Group (N=41) Total Experimental (N=42) Compliant Experimental (N=23)

 

Week Zero Week 16 Week Zero Week 16

Week Zero

Week 16
Total energy intake (kcal) 1,468±420

1,434±420

1,496±315 1,764±495, P<0.001 1,471±251 2,013±384, P<0.001

Protein intake (g)

56.7±17.7

57.1±15.4

56.7±16.1 

66.4±22.8 

56.8±15.0 

71.0±21.9 
Body weight (kg) 52.7±9.2 52.7±9.6 53.7±8.6  55.4±9.1, P<0.001  52.3±7.4  54.1±7.9, P<0.001 
Triceps skinfold (mm) 13.3±6.5 13.6±6.6 13.5±5.3 14.4±5.6  12.6±5.1 13.6±5.6 
Suprailiac skinfold (mm) 11.0±7.1 11.8±7.0 12.6±7.3  13.8±8.0  12.0±7.1  13.1±7.3 
Subscapular skinfold (mm) 14.3±7.6 15.4±8.5 14.8±6.4  16.0±7.1 14.2±6.1  15.5±6.9 
Calf circumference (cm) 31.3±2.9 31.1±2.9 31.5±2.7 31.6±2.9  30.8±2.8 31.0±2.7 
Arm muscle circumference (cm) 21.3±2.4 21.1±2.5 21.0±2.0 21.0±2.0  20.9±1.7  21.0±2.1 
Physical role functioning 54.3±36.2 (N=39) 69.5±37.7, P<0.01  46.2±39.6 63.1±35.0, P<0.01 45.6±37.4 71.7± 28.5, P<0.001
Emotional role functioning 71.5±38.4 (N=39) 75.4±35.8 72.2±38.9 84.1±31.4, P<0.01 72.5±38.5 84.1±31.6, P<0.05
Vitality 47.4±21.9 (N=39) 51.3±21.4 43.6±20.9 45.4±19.4 43.0±24.1 48.9±18.9, P<0.05

Other Findings

  • Among subjects randomized to the experimental group, 55% (23 of 42) achieved a mean increase in total energy intake of more than 250kcal per day over the study period and were considered to be compliant
  • The average weight gain was 1.62±1.77kg over the 16-week period in the treatment group (1.76±1.41kg in the compliant subgroup) vs. 0.04±1.47kg in the control group (P<0.0001)
  • Increased body weight was consistent with significant increase in energy intake in subjects in the experimental group (+269±434kcal with 165ml per day from liquid supplement) and in the compliant subgroup (+545±379kcal with 212ml per day from liquid supplement)
  • No significant changes were observed with respect to other anthropometric indices, muscle strength or functional variables; however, beneficial effects were observed in the number of days spent in bed (P=0.04). 
Author Conclusion:

Nutrition intervention is feasible in free-living, frail, undernourished elderly people and results in significant improvement of nutritional status with respect to energy and nutrient intake and weight gain. Weight loss can be stopped, and in some cases, reversed; however, increased physical activity may also be required to improve health and functional status.

Funding Source:
Industry:
Reviewer Comments:

Groups had statistically significant differences in age; this did not appear to be controlled for in the statistical analyses. Different numbers of subjects reported throughout the article. Only 55% of subjects in the experimental group considered to be compliant, and mean consumption of compliant group only 212ml per day, not the full can. SF-36 measurements were not made in all control subjects. Study funded by Abbott Laboratories, manufacturers of Ensure.

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) Yes
  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) Yes
 
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? ???
  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? No
  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? ???
  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? No
  4.4. Were reasons for withdrawals similar across groups? No
  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? Yes
  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? Yes
  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? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  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? Yes
  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? ???
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)? Yes
  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? No
  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? No
10. Is bias due to study's funding or sponsorship unlikely? ???
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? ???