CD: Quality of Life (2006)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To estimate the incidence of psychiatric disorders (anxiety and depression) in celiac disease patients on gluten withdrawal for at least 1 year and to evaluate the psychological weight of a chronic disease that involves a restrictive diet and a limited lifestyle, the acceptance of the disease, and the effects of both disease and diet on behavior and quality of life.
Inclusion Criteria:
Aged between 20 - 70 years, on gluten withdrawal for at least 1 year, normal clinical and hematochemical nutritional assessment, absence of any concomitant severe chronic disease.
Exclusion Criteria:
Excluded if not included above.
Description of Study Protocol:

Recruitment

100 unselected, consecutive celiac disease patients attending the outpatient malabsorption clinic of the Torino University Teaching Hospital.

Design

Cross-sectional study.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

Professional semi-structured interview and psychiatric questionnaires.

Statistical Analysis

Descriptive statistics presented as mean +/- standard deviation and as percentage of abnormal results.  Differences in frequencies analyzed using the chi-square or Fisher's exact test where indicated.  For comparison of means, unpaired Student's t test (or non-parametric Mann-Whitney U test and Wilcoxon signed rank test where data not normally distributed) were applied.  Pearson's coefficient (or Spearman's coefficient of rank correlation) used for correlation studies.  Effect of demographic variables on overall scores checked with multiple regression analysis.  Interrater agreement calculated by the K test. 

Data Collection Summary:

Timing of Measurements

3 groups of celiac disease patients, diabetic patients and healthy controls were assessed by a professional semi-structured interview based on DMS-IV criteria and psychiatric questionnaires.

Dependent Variables

  • Zung Self-Rating Depression Scale
  • State and Trait Anxiety Inventory
  • SF-36 Health Survey
  • Illness Behavior Questionnaire
  • Professional semi-structured diagnostic interview by the Structured Clinical Interview

Independent Variables

  • Gluten-Free Diet.  Compliance assessed through self-report as strict adherence, partial adherence or poor adherence.

Control Variables

 

Description of Actual Data Sample:

Initial N: 100 celiac disease patients, 25 men, 75 women.  100 asymptomatic volunteers and 100 patients with diabetes mellitus.

Attrition (final N):  See above.

Age:  mean age 40.4 years +/- 14.12 years, range 20 - 70 years 

Ethnicity:  Not specifically mentioned. 

Other relevant demographics:  Age at diagnosis was 32.3 +/- 14.5 years 

Anthropometrics:  Groups were comparable with respect to ethnic origin, socioeconomic status, and educational level.

Location:  Italy 

 

Summary of Results:

 

SF36 Subscale Celiac Disease Diabetes Healthy

t test between CD and DM

Physical Functioning 86.3 +/- 23.8 81.4 +/- 25.5 98.0 +/- 7.5 NS

Role Physical

83.5 +/- 28.9

81.1 +/- 34.7

92.6 +/- 20.9 NS
Bodily Pain 75.4 +/- 18.4 71.9 +/- 22.8 89.7 +/- 11.4 NS
Mental Health 66.2 +/- 18.7 66.9 +/ 19.7 76.8 +/- 16.3 NS
Role Emotional 81.6 +/- 31.6 84.4 +/- 32.6 90.0 +/- 26.7 NS
Social Functioning 76.6 +/- 22.6 76.3 +/- 23.2 87.2 +/- 20.9 NS

Vitality

63.2 +/- 18.7

61.4 +/- 20.1

70.8 +/- 16.3

NS

General Health

64.5 +/- 22.8

57.9 +/- 21.2

83.4 +/- 12.5

0.036

Other Findings

After 1 year, mucosal recovery was found in 19 patients (22.6%), appreciable improvement (type I) in 44 patients (52.4%), persistent partial atrophy (type II) in 13 patients (15.5%) and total villous (type III) atrophy in 8 patients (9.5%).

Self-reported adherence was considered strict for 82, partial for 16 and poor for 2 patients, no gluten intake for 49, occasional lapses for 48 and no compliance at all for 3 patients.

The modified Self-Rating Depression Scale and State and Trait Anxiety Inventory Y2 scores were significantly higher in both celiac and diabetic patients than in healthy controls.

The duration of gluten restriction was related to significantly higher modified Self-Rating Depression Scale scores in patients with a more recent diagnosis.

Quality of life was poorer in both celiac and diabetic patients than in healthy controls and significantly correlated with anxiety.

The Illness Behavior Questionnaire showed a high psychological and somatic perception of illness in both celiac and diabetic patients.  Its subscale scores correlated significantly with anxiety and depression symptoms.

Author Conclusion:
This study confirms that both depression and anxiety are common features among celiac disease patients.  In addition, depression and anxiety did not depend on diet compliance or demographic variables, depression tended to improve with time.  In celiac disease, psychiatric disorders should be ascribed to difficulties in adjusting to the chronic nature of the disease rather than directly to the disease itself, thus giving an indication for preventive liaison psychiatric interventions.
Funding Source:
University/Hospital: Universita degli Studi di Torino (Italy)
Reviewer Comments:
Large sample sizes.  Interrater reliability tested.
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? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  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%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  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? 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? N/A
  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? 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? 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? N/A
  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? 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)? N/A
  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