Researchers created and validated a Turkish questionnaire called DESTEK that measures dietitians’ knowledge, attitudes, and confidence about dietary supplements. The tool, tested with 223 Turkish dietitians, showed good reliability with an internal consistency score of 0.795 and identified four distinct competency areas. According to Gram Research analysis, the questionnaire accurately measures supplement-related competence, though larger studies are needed before widespread clinical use.
Researchers in Turkey created and tested a new questionnaire to measure how knowledgeable dietitians are about dietary supplements and how confident they feel giving advice about them. The tool, called DESTEK, was adapted from an English version and tested with 223 Turkish dietitians. The questionnaire measures four different areas: knowledge, attitudes, comfort level, and preparedness. According to Gram Research analysis, the tool showed good reliability and validity, meaning it accurately measures what it’s supposed to measure. This could help identify which dietitians need more training on supplements and improve the quality of nutrition advice in Turkey.
Key Statistics
A 2026 methodological study of 223 Turkish dietitians found that the DESTEK questionnaire demonstrated acceptable internal consistency with a Cronbach’s alpha of 0.795 for measuring supplement knowledge and preparedness.
The DESTEK questionnaire’s four-factor structure explained 38.3% of total variance in dietitian responses, with confirmatory factor analysis showing acceptable model fit (CFI = 0.915; RMSEA = 0.062).
Test-retest analysis of the DESTEK questionnaire with Turkish dietitians demonstrated acceptable temporal stability with an intraclass correlation coefficient of 0.772, indicating reliable measurement over time.
Composite reliability values for the DESTEK questionnaire ranged from 0.60 to 0.83 across four subscales measuring different aspects of dietitian supplement competence in Turkey.
The Quick Take
- What they studied: Whether a new Turkish questionnaire accurately measures dietitians’ knowledge, comfort, and readiness to advise patients about dietary supplements
- Who participated: 223 dietitians working in Turkey who completed the questionnaire twice to test if answers stayed consistent
- Key finding: The DESTEK questionnaire successfully measured four different areas of supplement competence with acceptable reliability (internal consistency score of 0.795) and showed good stability when retested
- What it means for you: If you see a Turkish dietitian, this tool could help identify whether they have the training needed to give you reliable advice about supplements. However, the study was limited to one country and used a moderate sample size, so larger studies are needed before widespread use
The Research Details
Researchers took an existing English questionnaire about dietitians’ supplement knowledge and adapted it for Turkish speakers. They made sure the language and cultural context made sense for Turkish dietitians. Then they gave the questionnaire to 223 dietitians in Turkey and analyzed the responses using statistical methods to see if the questions grouped together logically. They used a technique called exploratory factor analysis to find patterns in the data, which revealed that the questions naturally fell into four main categories. After identifying these categories, they used another statistical method called confirmatory factor analysis to confirm that this four-part structure actually worked well. They also tested the questionnaire twice with the same people to make sure answers were consistent over time.
Having a validated tool in Turkish is important because dietitians in Turkey need a reliable way to assess their own knowledge and comfort with supplements. This helps identify training gaps and ensures patients receive accurate information. The study’s careful approach to cultural adaptation means the tool actually fits Turkish healthcare settings rather than just being a direct translation
The study used established statistical methods to test the questionnaire’s quality. The sample size of 223 dietitians was adequate for this type of analysis. The questionnaire showed good internal consistency (0.795), meaning the questions reliably measured the same concepts. Test-retest reliability was acceptable (0.772), showing that answers stayed fairly consistent when people took the questionnaire again. However, the study was conducted only in Turkey with a moderate sample size, so results may not apply to other countries or larger populations
What the Results Show
The DESTEK questionnaire successfully identified four distinct areas that measure dietitians’ supplement competence. These four areas together explained 38.3% of the variation in how dietitians answered the questions. The overall questionnaire showed acceptable internal consistency with a Cronbach’s alpha of 0.795, which means the questions reliably measured what they were supposed to measure. Individual sections had consistency scores ranging from 0.531 to 0.824, with most sections performing well. The statistical tests confirmed that the four-part structure fit the data well, with a comparative fit index of 0.915 and other fit measures in acceptable ranges. When the same dietitians took the questionnaire again, their answers were similar (intraclass correlation coefficient of 0.772), showing the tool is stable over time.
The questionnaire demonstrated good composite reliability across all four sections, with scores ranging from 0.60 to 0.83. Discriminant validity was supported, meaning each of the four sections measured something different from the others rather than all measuring the same thing. The sampling adequacy was acceptable with a Kaiser-Meyer-Olkin measure of 0.78, indicating the data were suitable for the statistical analysis used. Bartlett’s test of sphericity was highly significant (p less than 0.001), confirming that the questions were related to each other in meaningful ways
This study adapted the English SCOPE questionnaire, which was previously developed and validated in English-speaking countries. The Turkish version (DESTEK) showed similar psychometric properties to the original, suggesting the adaptation successfully preserved the questionnaire’s ability to measure dietitian competence. The four-factor structure found in this Turkish study aligns with the multidimensional approach of the original tool, though the specific factors may reflect cultural differences in how Turkish dietitians approach supplement education
The study included only 223 dietitians, which is a moderate sample size. All participants were from Turkey, so results may not apply to dietitians in other countries. The questionnaire explained only 38.3% of the total variation in responses, meaning other factors not measured here also influence dietitian competence. Some subscales had lower internal consistency (0.531), suggesting those sections could be improved. The study did not test whether the questionnaire actually predicts how well dietitians advise patients about supplements in real practice
The Bottom Line
The DESTEK questionnaire can be used to assess Turkish dietitians’ knowledge, attitudes, and comfort with dietary supplements (moderate confidence level). It may help identify which dietitians need additional training on supplement topics. However, researchers recommend testing the tool with larger and more diverse groups of dietitians before using it widely in clinical settings or for high-stakes decisions
Turkish dietitians and nutrition educators should care about this tool because it helps identify knowledge gaps. Healthcare organizations in Turkey can use it to plan training programs. Patients may benefit indirectly by ensuring their dietitian has adequate supplement knowledge. This tool is less relevant for dietitians outside Turkey unless it’s adapted for their language and culture
The questionnaire can be administered and scored immediately, providing quick feedback about a dietitian’s competence level. However, improvements in actual supplement knowledge and patient advice would require follow-up training and would take weeks to months to show results
Frequently Asked Questions
What is the DESTEK questionnaire and what does it measure?
DESTEK is a Turkish questionnaire that measures four areas of dietitian competence regarding dietary supplements: knowledge, attitudes, comfort level, and preparedness. It was adapted from an English tool and tested with 223 Turkish dietitians to ensure it accurately measures what it’s supposed to measure.
How reliable is the DESTEK questionnaire for assessing dietitian knowledge about supplements?
The DESTEK questionnaire showed good reliability with an internal consistency score of 0.795 and test-retest stability of 0.772. These scores indicate the tool consistently measures dietitian competence, though researchers recommend further validation with larger and more diverse samples.
Can the DESTEK questionnaire be used outside of Turkey?
The DESTEK questionnaire was specifically adapted and validated for Turkish dietitians. While it could potentially be adapted for other languages and cultures, it would need its own validation study in each new setting to ensure it works properly.
What are the four areas that DESTEK measures in dietitians?
The DESTEK questionnaire measures four distinct competency areas: dietitian knowledge about supplements, their attitudes toward supplement education, their comfort level discussing supplements, and their perceived preparedness to advise patients about supplements.
How many dietitians participated in the DESTEK validation study?
The study included 223 Turkish dietitians who completed the questionnaire. This sample size was adequate for the statistical analysis, though researchers recommend testing with larger and more diverse groups before widespread clinical use.
Want to Apply This Research?
- If you’re a dietitian using a nutrition app, track your supplement education hours and knowledge assessments monthly using the DESTEK framework’s four areas: knowledge gained, attitude changes, comfort level improvements, and preparedness growth
- Dietitians can use the app to log supplement-related patient questions they encounter and identify which topics appear most frequently, then use those insights to prioritize their continuing education
- Retake the DESTEK questionnaire every 6 months after completing supplement-focused training to measure whether your knowledge, attitudes, and confidence have improved in specific areas
This research describes the development and testing of a questionnaire tool for Turkish dietitians. It does not provide medical advice about dietary supplements. Individuals should consult with a qualified healthcare provider or registered dietitian before starting any dietary supplement. The findings are based on a study of 223 Turkish dietitians and may not apply to other populations. Further research with larger and more diverse samples is needed before this tool is widely implemented in clinical practice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.