CD: Quality of Life (2006)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To evaluate self-perceived quality of life in adult celiac patients after at least 1 year of gluten-free diet.
Inclusion Criteria:
Members of Italian Celiac Society who were on a gluten-free regimen for at least 1 year.
Exclusion Criteria:
Excluded if not included above.
Description of Study Protocol:

Recruitment

Over 30 day period, members recruited from Italian Celiac Society.  60 - 70% of diagnosed patients join, most do not join if they do not live close to a regional center.

Design

Cross-sectional study.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

Subjects completed a modified version of the Zung Self-Rating Depression Scale.

Statistical Analysis

Evaluation of anxiety, depression, and positive attitude was obtained by summing 4 - 5 visual analog items exploring these areas into composite variables.  Medians and interquartile ranges were used to describe variables.  Normally distributed data were standardized for sex, age and age at diagnosis in a multivariate model where required.

Data Collection Summary:

Timing of Measurements

Subjects completed questionnaire.

Dependent Variables

  • Quality of life measured with modified version of Zung Self-Rating Depression Scale.  Not tested for validity or reliability.

Independent Variables

  • Gluten free diet for at least 1 year.  Compliance was self-reported.

Control Variables

 

Description of Actual Data Sample:

Initial N: 745 contacted

Attrition (final N):  581 patients (78% response rate), 410 females

Age: Mean age 31.5 +/- 11.2 years

Ethnicity: Not mentioned

Other relevant demographics:  Mean age at diagnosis was 23.2 +/- 14.8 years. Average duration of gluten-free diet was 8.26 +/- 3.2 years.

Anthropometrics (e.g., were groups same or different on important measures)

Location:  Italy 

 

Summary of Results:

Other Findings

96.9% correctly defined celiac disease as a chronic food intolerance. 

74.1% reported total adherence to a gluten-free diet, 21.5% on a fairly strict gluten-free regimen (1-3 transgressions/month) and 4.4% reported continuous transgressions.

Most felt well (83.6% "very well" and "well").  Anxiety, depression and happiness scores were low.

Most participants felt that a gluten-free life differentiated them from the general population.  Anxiety and depression scores were directly correlated with the feeling of being different from the population (r = 0.20, P = 0.001 for both), with the magnitude of uneasiness when sharing a table (r = 0.20, P = 0.001 for both), and inversely with the overall sensation of well-being (r = -0.23, P = 0.001 and r = -0.16, P = 0.01, respectively).

The depression score was inversely correlated with a satisfactory sex life (r = -0.22, P = 0.001).

In a multivariate model, anxiety was not related to age, educational level, work, compliance to diet, or sex life, whereas it was associated with the overall sense of well-being and the sense of being different from others.

Happiness was correlated with the overall sense of well-being (r = 0.16, P = 0.01).

Women and patients diagnosed after 20 years of age had better dietary compliance, but more problems in their social life.

Happiness scores were higher in patients diagnosed before 20 years of age.  Anxiety and depression were infrequent in this group; however, anxiety was frequently related to feeling different from the general population, and depression to an unsatisfactory sexual life.

 

Author Conclusion:
In conclusion, celiac disease does not appear to be associated with a low level of self-perceived quality of life in members of the Italian Celiac Society.  This study supports the hypothesis that adult treated celiacs who are members of the Italian Celiac Society may experience a good quality of life, even in Italy, where gluten containing food is a much appreciated staple of the diet.
Funding Source:
University/Hospital: University of Naples Federico II (Italy); Second University of Naples
Not-for-profit
0
Foundation associated with industry:
Reviewer Comments:
Large sample size.  Selection bias based on membership.  High response rate.  Modified questionnaire not tested for reliability and validity.  No comparison to controls.
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? ???
  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? 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? ???
  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? ???
  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? 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? 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? ???
  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? 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)? 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