Cochlear implantation (CI) is a surgical intervention to improve the hearing of patients with profound hearing loss. Due to the improvements in CI-technology and knowledge regarding surgery and CI fitting, speech recognition with CI has improved over the past decades. This has led to relaxation of the audiological implantation criteria. Whereas CI was initially indicated for patients with total deafness, currently also patients with moderate/severe-to-profound hearing loss are eligible for CI.~Moderate/severe-to-profound hearing loss has a negative effect on the patients' functioning. Because often hearing loss in adults is progressive, resulting in a decline in speech recognition, the disability might progress during this waiting time to a state in which societal participation can become even more difficult: the hearing loss might affect social participation, autonomy, work/occupational status and quality of life. However empirical data on this is not yet available. Timely intervention, like cochlear implantation may prevent societal drop out.~The societal impact of cochlear implantation for patients who are (currently) eligible for CI is unknown. It is imperative to obtain this data in order to secure treatment for those who need it. This multicenter cohort observational study is set up to investigate the impact of moderate/severe-to-profound hearing loss on societal related outcomes, defined as participation; communication profile; autonomy; cognition; listening effort; work; productivity loss; income; medical consumption; third party quality of life; quality of life, and capability. The primary aim is to investigate the effect of hearing rehabilitation with cochlear implantation on these societal related outcomes.~Castoredc (Castor electronic data capture) will be used for capturing research data. Questionnaires will be constructed in castors' online survey service and administered to participants online.~IBM SPSS Statistics and R studio software will be used for the statistical analysis. Descriptive analysis will be conducted to assess the baseline characteristics and the continuous variables will be summarized with mean ± SD or median (interquartile range) (if not normally distributed) and categorical variables with percentage (numbers). The statistical analysis for the primary objective, the differences in baseline(T0) and T2/T3/T4 for the primary outcome variables, we will use general linear models with the outcome (differences) as independent variable. To investigate the complete pattern in time of the effects we will use mixed models, in which time is an additional explanatory categorical variable. For the secondary objective the effect between baseline(T0) and T1, short before CI surgery will be investigated. General linear models with the outcome (differences) as independent variable.
The primary objective of this study is to determine the (long term) effect of intervention with a CI in adult participants with progressive postlingual moderate/severe-to-profound sensorineural hearing loss on societal related outcomes (participation; communication profile; autonomy; cognition; listening effort; work; productivity loss; income; medical consumption; third party quality of life; quality of life, and capability).~The secondary objective is to determine the effect of CI waiting time between referral and CI surgery on the same societal related outcomes, in the adults with postlingual moderate/severe-to-profound sensorineural hearing loss.