Psychometric validation of the Turkish version of the COugh Assessment Test (COAT) in individuals with substance use disorder

Cough is one of the most frequently reported respiratory symptoms among individuals with substance use disorder (SUD), and chronic cough markedly impairs quality of life through its secondary social, physical, and psychological consequences. This study aimed to translate the COugh Assessment Test (COAT) into Turkish and to evaluate its reliability and validity in individuals with SUD. The finalized Turkish version of the COAT was administered to a sample of 50 clinically stable individuals diagnosed with SUD. Internal consistency of the instrument was evaluated using Cronbach's alpha coefficient, and test-retest reliability was determined by administering the COAT on two separate occasions with a one-week interval between assessments. Construct and convergent validity were examined through Pearson correlation analyses between COAT total scores, peak cough rate (PCFR), and the Leicester Cough Questionnaire (LCQ). The COAT demonstrated acceptable internal consistency (Cronbach's α = 0.738) and excellent test-retest reliability (ICC = 0.889). Construct validity was supported by significant negative correlations with PCFR (r=-0.666, <i>p</i> < 0.001) and the LCQ (r=-0.578, <i>p</i> < 0.001). No floor or ceiling effects were identified, indicating appropriate score distribution and measurement sensitivity. The Turkish version of the COAT demonstrated strong psychometric properties, confirming its validity and reliability as an instrument for evaluating cough-related quality of life in individuals with SUD. Moreover, the use of COAT may enhance patient-clinician communication and contribute to more effective symptom monitoring and management strategies.