NCT07344649

Turkish Validation of the Nijmegen Questionnaire in COPD

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 90 (estimated)
• Sponsor: Saglik Bilimleri Universitesi · Academic / Other
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Not accepted

Summary

Dysfunctional breathing is a common and clinically relevant problem in patients with chronic obstructive pulmonary disease (COPD), contributing to increased dyspnea perception, reduced exercise tolerance, and impaired quality of life. The Nijmegen Questionnaire (NQ) is a widely used symptom-based instrument for screening dysfunctional breathing; however, a validated Turkish version for patients with COPD is currently unavailable. This observational methodological study aims to translate, culturally adapt, and evaluate the validity and reliability of the Turkish version of the Nijmegen Questionnaire (NQ-TR) in individuals with stable COPD.

Detailed description

This single-center observational study will be conducted in patients with clinically stable COPD. The study consists of two main phases: (1) translation and cultural adaptation of the Nijmegen Questionnaire following international guidelines for patient-reported outcome measures, and (2) psychometric evaluation of the Turkish version in a COPD population. The translation process includes forward translation, reconciliation, back-translation, developer review, cognitive debriefing with patients, and final proofreading. After completion of the linguistic adaptation, the NQ-TR will be administered to eligible participants at baseline and repeated after one week in clinically stable individuals to assess test-retest reliability. Construct validity will be evaluated using exploratory and confirmatory factor analyses. Convergent validity will be assessed by examining correlations between NQ-TR scores and established clinical measures, including the COPD Assessment Test (CAT), Modified Medical Research Council (mMRC) Dyspnea Scale, Hospital Anxiety and Depression Scale (HADS), and Dyspnea-12 (D-12). Internal consistency, test-retest reliability, and measurement stability will be analyzed.

Conditions

• COPD

Interventions

Type	Name	Description
OTHER	Questionnaires	Administration of validated self-reported questionnaires (Nijmegen Questionnaire, CAT, mMRC, HADS, Dyspnea-12)

Timeline

• Start date: 2026-04-13
• Primary completion: 2027-01-01
• Completion: 2027-01-01
• First posted: 2026-01-15
• Last updated: 2026-04-15

Locations

1 site across 1 country: Turkey (Türkiye)