Validation of the Turkish version of the Celiac Disease Questionnaire (CDQ)

Abstract

IntroductionThe aim of the study was to translate, adapt and validate the Celiac Disease Questionnaire (CDQ), which was developed in Germany, for use in Turkey.MethodsThe questionnaire was translated by a forward-backward translation method. Total CDQ score and four subscores (emotional state, gastrointestinal symptoms, worries, social problems) were calculated and their reliability assessed by internal consistency. Reliability of scales was evaluated by internal consistency. Test-retest reliability was assessed by means of a retest after 15 days. Face validity was assessed by patient volunteers and physicians and construct validity was assessed by means of confirmatory factor analysis. Convergent validity was determined by comparing responses to the CDQ with similar subscale scores of the Short Form-36 (SF-36) health survey. Discriminative concurrent criterion validity was determined by comparing the CDQ scores of patients with celiac disease (CD) on a gluten-free diet (GFD) with CD patients not on a GFD.ResultsThe Turkish version of the CDQ was completed by 205 patients with celiac disease (Female 146, mean age 31.1 year, ± 10.61). The Cronbach-α coefficent of the subscores ranged between 0.73 and 0.93. Test-retest reliability was 0.99 for all subscores. 42 patients with CD and five gastroenterologists assessed the items of the CDQ to be comprehensible and relevant to the health related quality of life (HRQOL) of CD patients. The confirmatory factor analysis demonstrated acceptable fit indices for the original four subscales of the CDQ. The correlations between the scales of the CDQ and the instrument for validation covering similar dimensions of the HRQOL ranged between 0.61 and 0.93. In all subscores and in the total score, patients not on a GFD showed a significantly reduced HRQOL (all p < 0.05) compared to patients on a GFD.ConclusionThe Turkish version of the CDQ proved to be a reliable and valid instrument for measuring HRQOL in Turkish patients with celiac disease.Electronic supplementary materialThe online version of this article (doi:10.1186/s12955-015-0272-y) contains supplementary material, which is available to authorized users.

Quality of life in coeliac disease: item reduction, scale development and psychometric evaluation of the Coeliac Disease Assessment Questionnaire (CDAQ)

“…When assessed against Terwee et al's quality criteria, the CDAQ received a positive rating. The results indicate that the test‐retest reliability of the CDAQ appears superior to the CD‐QOL, for the Cohen's Kappa coefficient was not sufficient (0.63), and at least comparable with the CDQ, for which some evidence of sufficient test‐retest reliability was found . However, the quality of some of the studies for both measures was poor with small sample sizes or insufficient detail about study design.…”

“…Across both surveys, the internal consistency of all five subscales was within the ideal range (0.7‐0.95) . Other coeliac‐specific measures have also been found to be internally consistent such as the CDQ and the CD‐QOL . However, despite some involvement of people with coeliac disease in the development, the CDQ has not been developed on the basis of in‐depth interviews or focus groups, which are the recommended approach by the US Food and Drug Administration…”

Nutritional Status and Health-Related Quality of Life in Adult Patients With Celiac Disease

“…A higher score indicates a higher quality of life. The highest score possible was 196 points, with 49 points for each subscale (Aksan et al, 2015;Häuser et al, 2007;Marchese et al, 2013;Zampieron et al, 2011). The Turkish version of the CDQ was adapted and validated by Aksan et al (Aksan et al, 2015).…”

The application of the Multi-Touch pad for the evaluation of the fine motor activity of the wrist

“…3) дискриминативная валидность как показатель избирательной корреляции со шкалами, имеющими отношение лишь к тонкой моторике, определялась путем отсутствия значимого коэффициента корреляции Спирмена с иными шкалами [10], например, со шкалой Ривермид; 4) надежность повторного тестирования определялась по оценке внутриклассового коэффициента корреляции (Intraclass Correlation Coefficients -ICC) [9][10][11][12]: значение менее 0,25 показывает плохую надежность, 0,4-0,75 -хорошую, 0,75 и выше -превосходную [13]; 5) важность изменений, происходящих в методе, вычислялась с помощью: а) определения стандартной ошибки измерения (Standard Error of Measurement -SEM) -мера надежности, оценивающая стабильность ответа. SEM рассчитывается по формуле [12][13][14]: SEM=SD•√(1 -R), где SD -это стандартное отклонение для всех наблюдений, R -ICC.…”

“…SEM оценивается в единицах, используемых в измерении, чем меньше показатель SEM, тем более точная оценка [14]; б) определения минимально заметных изменений (Minimal Detectable Change -MDC) -оценка наименьшего количества изменений, которые могут быть обнаружены с помощью измерения, соответствующего заметному изменению способностей. MDC 95 основано на 95% доверительном интервале (ДИ) и вычисляется на основе SEM по формуле [10,12,13]:…”