| Background. The cochlear implant represents one of the most consequential applications of medical devices to humans, especially when the cochlear implantation of young, deaf children is considered. What are the critical outcomes that need to be assessed after early pediatric cochlear implantation (CI) and how can they be measured? The potential impact of this expensive (re)habilitative intervention in early development and consequent life effects forces a critical appraisal of what outcomes are chosen to guide parental, clinical, and socioeconomic decisions. Current evaluative approaches for pediatric cochlear implantation have arisen from historical models of deafness and hearing---paradigms that are now outdated by contemporary approaches to the treatment of disability and functioning.;Methods. We used a conceptual model of functioning developed by the World Health Organization to provide a framework for understanding the role of current outcome measures and to identify deficits in the current evaluation paradigm. Using an established database of speech and language outcomes in 188 cochlear-implanted children, we explored with cross-sectional parametric and nonparametric regression models how current outcome measures reflect parental perceptions of development one year after cochlear implantation. Health-related quality of life (HRQL) measures were then explored in a systematic review of the pediatric CI literature in order to probe the validity and generalizability of prior assessments of functional performance after early CI. Finally, using both qualitative and quantitative psychometric methods, we developed and tested a de novo unidimensional scale of communicative performance for ≤5 year-old children with cochlear implants. Qualitative instrument I development was based on a systematic review of the literature, focus groups, and semistructured interviews with the parents of cochlear-implanted children and deafness experts. Further refinement and testing of the psychometric validity of the draft instrument was conducted using factor and regression analysis with a cross-sectional sample of 75 parents of CI children.;Results. Current outcome measures were focused on body functions (hearing and speech) and communicative capacity (language). Outcome measures of real-world communicative performance were not available. Associations between parental perceptions of development and broader language measures were more robust than with closed-set speech. We found that HRQL metrics had been poorly applied to outcomes assessment in pediatric CI and that multiple methodological and conceptual issues limited their application to ≤5 year-old cochlear-implanted children. Based on insights from studying these previous instruments, we developed the 23-item Functioning after Pediatric Cochlear Implantation (FAPCI) instrument that represents a unidimensional scale of the real-world communicative performance of 2-5 year-old CI children. The scale demonstrated excellent reliability (Cronbach's alpha ≥ 0.86), and there was strong evidence supporting the instrument's nomological validity. FAPCI scores were positively associated with duration of implant use (p < 0.001), and 4 years of implant use were required before maximal FAPCI scores were achieved.;Conclusions. Assessing communicative performance in addition to speech and language enables the comprehensive assessment of functioning and provides insights into the cochlear-implanted child from the parental perspective. By measuring communicative performance, the dynamic interaction between environmental and clinical factors on a child's communicative abilities within a biopsychosocial model of functioning can be studied and appropriate interventions developed. Optimizing a cochlear-implanted child's early functional abilities provides the best chance for long-term success in educational and vocational opportunities and quality of life. Importantly, the methods developed herein can inform parents who as decision-makers are placed in a time-sensitive and crucial position in choosing an interventional strategy for their deaf child. |
