Changes on clinical and participatory outcomes in people with severe-to-profound hearing loss after cochlear implantation: protocol of a multicentre prospective observational cohort study - Societal Merit of Intervention on Hearing Loss Evaluation (SMILE)

Abstract

Introduction: Cochlear implantation (CI) is a (cost-)effective intervention for people with severe or profound hearing loss. Since its introduction experience increased and the technology evolved, leading to better results and relaxation of CI eligibility criteria. Meanwhile, with national healthcare costs increasing there is a need for evidence of healthcare technology's value. This protocol describes a study to investigate clinical and participatory outcomes after CI for the currently (expanded) eligible hearing impaired population. The study adds to the current evidence base through its multicentre design, long-term follow-up and use of participatory outcomes alongside standard clinical outcomes.

Methods: This multicentre prospective observational cohort study will include at least 156 adult patients with severe-to-profound hearing loss, approximately evenly divided into two groups (1, ages 18-65 years and 2, age >65 years). The measurements consist of audiometry, cognition tests, listening effort tests and multiple generic and disease specific questionnaires. Questionnaires will be administered twice before CI, soon after inclusion at CI referral and shortly before CI surgery, with an annual follow-up of 3 years after CI. The Impact on Participation and Autonomy questionnaire will be used to assess participation. Generalised models (linear, logistic, Poisson) will be used. Mixed effects models will be used to investigate changes over time while exploring differences in subgroups and the influence of covariates.

Ethics and dissemination: The study has received ethical approval from the Medical Ethical Committee of all participating centres. The results could provide valuable insights into changes in participatory outcomes of people with severe-to-profound hearing loss after CI. Results will be disseminated through peer-reviewed journals, scientific conferences and professional and patient organisation meetings.

Trial registration number: NCT05525221.

Keywords: Adult otolaryngology; Decision Making; HEALTH ECONOMICS; Otolaryngology; Patient Participation; Quality of Life.

Figure 1

SMILE study timeline. Questionnaires will be conducted at each time point. Audiometric data will be gathered in line with clinical practice guidelines. Cognition tests will be measured once preoperative and once postoperative if age is <65 years and twice postoperative if age is >65 years. Pupillometry will be conducted only postoperative. CI, cochlear implantation; CPHI, Communication Profile for the Hearing Impaired; HUI3, Health Utility Index Mark 3; IPA, Impact on Participation and Autonomy; NCIQ, Nijmegen Cochlear Implant Questionnaire; QEEW, Questionnaire on the Experience and Evaluation of Work; EQ-5D-5L, EuroQol 5 Dimensions 5 levels; iPCQ, iMTA (Institute for Medical Technology Assessment) Productivity Cost Questionnaire; iMCQ, iMTA (Institute for Medical Technology Assessment) Medical Consumption Questionnaire; RBANS-H Repeatable Battery for the Assessment of Neuropsychological Status for Hearing Impaired Individuals.