Study Protocol: Psychometric Testing of the German Vestibular Schwannoma Quality of Life Index-A Multicenter Study on Quality of Life and Patient-Centered Care in Vestibular Schwannoma.

Vestibular schwannomas (VSs) are benign tumors of the vestibulocochlear nerve that often cause significant neurological and functional impairment, affecting patients' overall quality of life (QoL). While clinical assessments have traditionally focused on hearing preservation and tumor control, patients often emphasize other critical symptoms such as dizziness, pain, cognitive difficulties and satisfaction with care. Therefore, patient-centered care that addresses the full range of patient experiences is essential. Despite its importance, patient-centered care in VS remains underexplored. This study will address this gap by psychometrically validating the German version of the Vestibular Schwannoma Quality of Life (VSQOL) Index, a newly developed QoL tool that includes key patient-centered domains. The primary objective is to validate the reliability and validity of the German VSQOL Index. The secondary aim is to assess VS patients' experience of patient-centered care and its impact on their well-being. This multicenter, cross-sectional study will involve German-speaking VS patients from several clinical centers in Germany and Switzerland as well as an online cohort. Psychometric testing of the German VSQOL will include reliability assessments (e.g., Cronbach's alpha, test-retest reliability), confirmatory factor analysis and convergent validity. In parallel, the study will assess patient-centered experiences of care using the EPAT questionnaire. Ethical approval has been obtained and all participants will be asked to provide written informed consent. The results will be shared through scientific publications and conferences, as well as with patient groups, in order to support improvements in clinical care.