CD: Quality of Life (2006)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To assess the burden of illness as perceived by celiac men and women living on a gluten-free diet for 10 years.
Inclusion Criteria:
Patients had diagnosis confirmed by a jejunal biopsy showing a flat mucosa.  They were started on a gluten-free diet and the early clinical response was unequivocal.  Remission by 8 -12 years was ascertained by a normal or borderline repeat biopsy in 84% or by negative tests for gliadin and endomysial antibodies in remaining patients unwilling to undergo repeat biopsy.
Exclusion Criteria:
Patients with concomitant dermatitis herpetiformis were not included.
Description of Study Protocol:

Recruitment

All eligible men and women diagnosed with celiac disease in the routines at 6 Swedish hospitals between 1984 and 1988 and proven to be in remission 8 - 12 years later.  Controls recruited from 3 local outpatient clinics.

Design

Cross-sectional study.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

Gluten-free diet or dietary therapy for type 2 diabetes for 10 years.

Statistical Analysis

All data presented as mean +/- SEM.  The distribution of the scores were skewed, indicating need for nonparametric statistical tests in subsequent analyses.  The relationships of the scale scores were therefore examined using Spearman's rank correlation, and paired comparisons were investigated by the Wilcoxon signed rank test.  Significance set at the 5% level.

Data Collection Summary:

Timing of Measurements

Subjects examined with SF-36 questionnaire and Burden of Illness questionnaire comprising perceived worries, restrictions and subjective outcome.

Dependent Variables

  • Subjective health assessed with Short Form 36 Health Survey (SF-36) questionnaire
  • Burden of illness assessed with 9-item questionnaire on 6-point Likert scale, developed by reseachers with reliability tested by Cronbach's alpha coefficient of 0.73 and construct validity correlation of r = -0.52 (P < 0.001) between the burden of illness scores and Psychological General Well-Being index

Independent Variables

  • Gluten-free diet and diabetic diet:  not defined or monitored.

Control Variables

 

Description of Actual Data Sample:

Initial N: 68 celiac patients (34 women, 34 men).  68 age- and sex-matched controls with type 2 diabetes.

Attrition (final N): See above.

Age:  Celiac patients:  mean age 57 years, range 32 - 75.  Controls:  mean age 57 years, range 29 - 76. 

Ethnicity:  Not mentioned. 

Other relevant demographics:  Not mentioned. 

Anthropometrics:  Age- and sex-matched controls.

Location:  Sweden 

 

Summary of Results:

Burden of Illness Sum Scores

Celiac Disease Type 2 Diabetes
Women 22.4 (6.33), P < 0.001 20.5 (4.35)
Men 17.9 (3.43) 21.2 (5.29)

Other Findings

The importance of complying with the diet was ranked similarly high by male and female celiac patients.

However, women were less satisfied with the outcome at 10 years than men were, and expressed more concern about the need to gain more knowledge about the disorder, the impact on socializing with friends, having to abstain from important things in life and the possibility that their children could get the disorder.  None of these aspects distinguished male and female diabetic patients.

Celiac women showed a higher burden of illness score than men did (P < 0.001), and this was inversely related to their SF-36 General Health, Vitality and Mental Health scores.

Author Conclusion:
In conclusion, we found that women living with celiac disease for several years perceive a greater burden of illness than men do.  There is little to support that poor adaptation to being celiac could be attributed to reduced internal resources in terms of impaired intellectual functioning or a deviate personality pattern.  Instead, depressiveness appears to be by far the most common neuropsychiatric complication among treated adults.  Helping them to cope with their disorder is a growing task for all reviewing such people.  Possibly launching problem-oriented education programmes, long used in the care of patients with diabetes, could be helpful in this regard.
Funding Source:
Government: Medical Research Council of Southeast Sweden
Reviewer Comments:
Dietary compliance not defined or monitored.  Questionnaire developed for the study.
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? 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.) 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? N/A
  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.) N/A
  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? 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? No
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? Yes
  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? ???
  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? ???
  7.5. Was the measurement of effect at an appropriate level of precision? ???
  7.6. Were other factors accounted for (measured) that could affect outcomes? ???
  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? Yes
  10.2. Was the study free from apparent conflict of interest? Yes