UWL: Association With Outcomes (2009)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
  • To analyze data on cognitive status, self-care ability and living situation in the three-field studies in 1989, 1993 and 1999 and relate them to nutritional status in 1999
  • It was hypothesized that nutritional status, as assessed by MNA, was related to functional status and to cognitive status, but not significantly affected by living arrangement
  • Additionally, authors hypothesized that relationships between cognitive status and self-care ability, between self-care ability and living situation and between cognitive status and living situation would be stronger with increasing age.
Inclusion Criteria:

Elderly men and women who participated in all three data collections of the SENECA study in 1989, 1993 and 1999.

Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

Elderly men and women who participated in all three data collections of the SENECA study in 1989, 1993 and 1999. The SENECA study on nutrition in the elderly is a longitudinal survey designed to measure dietary patterns of elderly living in different European small towns and to examine the relationship between diet and various measures of health and performance in a randomized sample of subjects of both sexes born in the period of 1913 to 1918, stratified by age and sex.

Design

Longitudinal study.

Statistical Analysis

  • Statistical analysis included measures of central tendency, chi-square statistics, T-tests, ANOVA and logistic regression
  • Logistic regression models were used to estimate the association between nutritional status (well-nourished or at nutritional risk) and selected lifestyle characteristics
  • A model was constructed for the whole population as well as males and females separately.
Data Collection Summary:

Timing of Measurements

Data was collected in the SENECA study in 1989, 1993 and 1999, by trained interviewers using a structured interview schedule. 

Dependent Variables

Nutritional status was categorized as being well-nourished (MNA above 24) or at nutritional risk (MNA below 24), using the 18-item mini-nutritional assessment questionnaire.

Independent Variables

  • Functional status: Diminished self-care ability was defined as the inability to perform all seven self-care items on the ADL instrument (walk between rooms, use the toilet, wash self, dress and undress, get in and out of bed, feed self and cut toenails)
  • Cognitive status: Respondents were deemed to have possible cognitive impairment if they scored below 24 on the mini-mental state examination (MMSE)
  • Living arrangement: Residence situation was categorized as either living alone, with spouse or partner or with others.

Control Variables

  • Sex
  • Living alone vs. other situations
  • MMSE over 24 vs. MMSE under 24
  • Able to do all seven self-care ADLs vs. not able to do all seven.
Description of Actual Data Sample:
  • Initial N: Unclear: 627 elderly men and women completed all three phases. 288 men and 339 women are included in the analysis.
  • Attrition (final N): As above
  • Age: 80 to 85 years old
  • Ethnicity: Not described.

Anthropometrics

There were wide differences between countries in several areas.

Location

Participants resided in 10 traditional towns in nine European countries:

  • Hamme, Belgium HB
  • Roskilde, Denmark RDK
  • Haguenau, France HF
  • Romans, France RF
  • Padua, Italy PI
  • Culemborg, the Netherlands CNL
  • Vila Franca de Xira, Portugal VP
  • Betanzos, Spain BE
  • Yverdon, Switzerland YCH
  • Marki, Poland MPL.
Summary of Results:

Logistic Regressions of Nutritional Risk Among Total Sample of Subjects

Lifestyle Characteristic

Total Sample (N=537)

Females (N=286)

Males (N=251)

Female Gender

OR=1.08 (95% CI:  0.97, 1.19)

N/A N/A
Living Alone OR=1.04 (95% CI:  0.93, 1.15)  OR = 0.89 (95% CI:  0.75, 1.03) OR=1.23 (95% CI: 1.06, 1.40)
Diminished Cognitive Function OR=2.10 (95% CI: 1.98, 2.22), P<0.05 OR = 1.77 (95% CI:  1.61, 1.93) OR=2.65 (95% CI: 2.46, 2.84)

Diminished Self-Care Ability

OR=2.44 (95% CI: 2.32, 2.56), P<0.001

OR=2.06 (95% CI: 1.90, 2.22), P<0.05

OR=2.93 (95% CI: 2.76, 3.10), P<0.01

Other Findings

  • There was wide variation between study locations in the percentage of respondents with possible cognitive impairment. This ranged from 4% to 39%, with an average of 16%.
  • There was wide variation between study locations in percent of respondents able to do all seven self-care tasks. This ranged from 42$ to 90% with an average of 61%.
  • The percentage of people at nutritional risk in 1999 also ranged widely by survey location, with an overall percentage of 24%
  • Nutritional risk was found to be associated with diminished cognitive status and diminished self-care ability, but was not associated with living alone
  • The relationship between self-care status (seven items) and nutritional status (MNA) was highly significant for both genders
    • Males: Odds ratio, 2.93; 95% CI, 2.76 to 3.10; P<0.01
    • Females: Odds ratio 2.06, 95% CI, 1.90 to 2.22; P<0.05.
  • Elderly people with diminished cognitive function and diminished self-care ability had a more than two times higher risk of being at nutritional risk
  • In addition, the strength of the relationships between cognitive status and self-care ability, self-care ability and living situation and cognitive ability and living situation all increased over time
  • In 1999 only 31% of the females and 49% of the males were able to do all seven self-care tasks, down from 61% and 78% in 1993, which was down from 75% and 83% in 1989, respectively
  • In all three surveys, more females than males were not able to do all seven tasks (P<0.05 in 1989; P<0.001 in 1993; P<0.001 in 1999)
  • In the oldest old, lifestyle characteristics and functional ability appeared to be strong predictors of risk for malnutrition than in younger adults.
Author Conclusion:
  • Overall, decreased cognitive and functional status is associated with both greater dependency relative to living situation and increased risk of malnutrition
  • Elderly people with diminished cognitive function and diminished self-care ability had a more than two times higher risk of being at nutritional risk than those without similar limitations
  • However, measures associated with nutritional status, including MNA scores, did not differ by living situation either for the total group or for either gender
  • In addition, nutritional status, as measured by MNA, did not differ by gender in this study of 80- to 85-year-old persons.
Funding Source:
Other: Not reported
Reviewer Comments:
  • Initial N unclear
  • Authors note the following limitations:
    • Wide cross-site differences existed for the variables in this study and all analyses were combined. Thus, some of the conclusions may not truly represent the practices and status of subjects in some locations.   
    • Data from the SENECA study are only of limited value to study the development of disabilities in so far as there was a tendency that respondents represented the healthier portion of the elderly population.
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? ???
  2.2. Were criteria applied equally to all study groups? ???
  2.3. Were health, demographics, and other characteristics of subjects described? No
  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? No
  4.1. Were follow-up methods described and the same for all groups? No
  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%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? No
  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? Yes
  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? 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? 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