CD: Quality of Life (2006)

Citation:

Johnston SD, Rodgers C, Watson RGP.  Quality of life in screen-detected and typical coeliac disease and the effect of excluding dietary gluten.  Eur J Gastroenterol Hepatol 2004; 16(12): 1281-1286.

PubMed ID: 15618833
 
Study Design:
Non-Randomized Controlled Trial
Class:
C - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To determine a measure of the quality of life in patients diagnosed as having celiac disease detected both by screening and those presenting clinically with typical clinical symptoms and to determine whether this improved after a period during which dietary gluten was excluded. 
Inclusion Criteria:

Subjects with positive and negative serology in the MONICA survey, and who agreed to have an endoscopic duodenal biopsy, were asked to complete the SF-36 questionnaire prior to biopsy, as well as all patients undergoing endoscopic duodenal biopsy on account of clinical symptoms.  Celiac disease diagnosed as at least severe partial, sub-total or total villous atrophy on duodenal biopsy.  Healthy subjects selected from a general practice population with negative celiac serology. 

Exclusion Criteria:
Included if not excluded above.
Description of Study Protocol:

Recruitment

Subjects recruited as a follow-up to a serological screening study.

Design

Nonrandomized Trial.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

SF-36 questionnaires completed after gluten-free diet for 1 year and compared to healthy controls.

Statistical Analysis

Comparisons between groups performed by means of Mann Whitney U test, and comparisons between the same subjects at 2 different time points were performed using Wilcoxon's matched pairs test.

Data Collection Summary:

Timing of Measurements

Questionnaire completed at diagnosis and in subjects agreeing to undergo duodenal biopsy as a follow-up to serological screening program.  Compared to healthy controls.

Dependent Variables

  • Quality of life measured with SF-36

Independent Variables

  • Gluten-free diet.  Compliance checked through anti-endomysial antibodies after 1 year.

Control Variables

 

Description of Actual Data Sample:

Initial N: 14 screen-detected celiac patients (4 male) compared with 23 controls (10 male).  17 clinically diagnosed celiac patients (5 male) compared with 26 controls (5 male).

Attrition (final N):  See above.

Age:  Screen-detected celiac patients mean age 52.4 years, controls mean age 51.5 years.  Clinically diagnosed celiac patients mean age 45.2 years, controls mean age 49.0 years.  

Ethnicity:  Not mentioned. 

Other relevant demographics:  Not mentioned. 

Anthropometrics:  Not mentioned.

Location:  United Kingdom 

 

Summary of Results:

Other Findings

Serology was negative for IgA AGA and IgA EMA in 11 of the 14 screen-detected celiac patients and in 11 of the 17 clinically diagnosed celiac patients at 1 year follow up.

There were no significant differences between the 8 SF-36 parameters when the screen-detected celiac patients were compared to controls, and at 1 year follow-up compared to their baseline data.

General health, vitality and role emotional were significantly lower in typical celiac patients compared with controls; general health and vitality improved significantly in typical celiac patients at 1 year compared to baseline.

General health with reference to 1 year previously significantly improved in typical celiac patients (3.8 vs 2.2; P = 0.0004) but not screen-detected celiac patients (2.9 vs 2.4, P = 0.08).

Author Conclusion:
Quality of life in screen-detected celiac patients did not differ significantly compared to controls.  2 of 8 Quality of Life parameters improved significantly in typical celiac patients compared to baseline data.  Dietary gluten exclusion in typical celiac patients led to a significant improvement in health at 1 year follow up, in contrast to screen-detected celiac patients.  Our study raises a problem for the case for population screening for celiac disease, since screen-detected celiac patients do not feel a subjective improvement in their general health and they may therefore be less willing to adhere to a strict gluten-free diet.
Funding Source:
Government: CDC
Reviewer Comments:
SF-36 used, validated instrument.  Small sample sizes, samples not well defined.  Compliance checked with antibodies.
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? ???
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
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? ???
  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? 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? 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