The validity and reliability of the Thai version of the Cochlear Implant Quality of Life questionnaire.

Objective Improving quality of life is one of the most important outcomes following cochlear implantation, and this can be effectively evaluated using disease-specific questionnaires. However, no such quality of life questionnaire currently exists in the Thai language for cochlear implant recipients. This study aimed to translate and validate the Cochlear Implant Quality of Life questionnaire into Thai.

Methods The original Cochlear Implant Quality of Life questionnaire consists of 35 items across six subdomains. The translation followed Hall's guideline for cross-cultural adaptation. Content validity was reviewed by three experts and 10 healthy participants.

Results After the translation process, the Thai version of the Cochlear Implant Quality of Life demonstrated strong content validity, achieving an Index of Item-Objective Congruence score of 1.0 across all items as assessed by three experts. A review by 10 healthy participants using a five-point Likert scale yielded a mean score of 4.71 (SD = 0.20; range: 4.35-5.00), confirming item clarity and relevance. In testing with 19 cochlear implant users, the Thai version of the Cochlear Implant Quality of Life demonstrated high internal consistency (Cronbach's alpha > 0.6) and good test-retest reliability (r > 0.75) across most subdomains. Moderate reliability was observed in three subdomains: communication (r = 0.512), environment (r = 0.745), and listening effort (r = 0.426).

Conclusion The Thai version of the Cochlear Implant Quality of Life is a valid and reliable instrument for assessing quality of life in adult cochlear implant users. It is suitable for use in clinical settings for Thai-speaking cochlear implant patients.