Development of the Cochlear Implant Quality of Life Item Bank

Functional outcomes following cochlear implantation have traditionally been focused on word and sentence recognition, which, although important, do not capture the varied communication and other experiences of adult cochlear implant (CI) users. Although the inadequacies of speech recognition to quantify CI user benefits are widely acknowledged, rarely have adult CI user outcomes been comprehensively assessed beyond these conventional measures. An important limitation in addressing this knowledge gap is that patient-reported outcome measures have not been developed and validated in adult CI patients using rigorous scientific methods. The purpose of the present study is to build on our previous work and create an item bank that can be used to develop new patient-reported outcome measures that assess CI quality of life (QOL) in the adult CI population.

An online questionnaire was made available to 500 adult CI users who represented the adult CI population and were recruited through a consortium of 20 CI centers in the United States. The questionnaire included the 101 question CIQOL item pool and additional questions related to demographics, hearing and CI history, and speech recognition scores. In accordance with the Patient-Reported Outcomes Measurement Information System, responses were psychometrically analyzed using confirmatory factor analysis and item response theory.

Of the 500 questionnaires sent, 371 (74.2%) subjects completed the questionnaire. Subjects represented the full range of age, durations of CI use, speech recognition abilities, and listening modalities of the adult CI population; subjects were implanted with each of the three CI manufacturers' devices. The initial item pool consisted of the following domain constructs: communication, emotional, entertainment, environment, independence, listening effort, and social. Through psychometric analysis, after removing locally dependent and misfitting items, all of the domains were found to have sound psychometric properties, with the exception of the independence domain. This resulted in a final CIQOL item bank of 81 items in 6 domains with good psychometric properties.

Our findings reveal that hypothesis-driven quantitative analyses result in a psychometrically sound CIQOL item bank, organized into unique domains comprised of independent items which measure the full ability range of the adult CI population. The final item bank will now be used to develop new instruments that evaluate and differentiate adult CIQOL across the patient ability spectrum.