The objective is to determine if eligibility (as defined as the duration of severe to profound hearing loss before cochlear implantation [CI]) has changed over the 30 years since Food and Drug Administration approval.Data Sources:
English-language, peer-reviewed articles, theses, and trial data available through PubMed and Cochrane Library databases up until and including May 31, 2016.Study Selection:
One thousand six unique articles were identified. Prospective studies that reported duration of severe/profound hearing loss before CI in adult patients were included. Retrospective studies, reviews, meta-analyses, articles reporting pediatric or mixed data, hybrid/electroacoustic CI, and articles from centers outside the United States were excluded. Seventy-one studies met inclusion criteria and were included for analysis.Data Extraction:
Contributing authors independently reviewed included studies for data validity and applicability.Data Synthesis:
Metaregression was used to assess the relationship between the year of publication and duration of hearing loss. To account for a possible age effect, a second model was estimated including mean age at the time of study as a covariate.Conclusion:
A positive association between study year and the duration of hearing loss before implantation was found showing a 0.28-year increase in the duration of hearing loss for every increasing study year. Contrary to conventional assumption, duration of eligibility for CI appears to be increasing. Though the reasons for this are not clear, current strategies to increase both awareness and access to CI seem to be falling short.