Audiology Practices in the Preoperative Evaluation and Management of Adult Cochlear Implant Candidates

Currently, no clear guidelines exist regarding clinical testing methods for identifying adult cochlear implant (CI) candidates. Indications provided by the US Food and Drug Administration, Medicare, and private insurers are ambiguous concerning test materials and the level and mode of test presentation. This could lead to wide variability in clinical assessment and, potentially, unequal access to CIs for individuals with clinically significant hearing loss.

To examine the preoperative testing methods used by audiologists in evaluating adult CI candidates across the United States.

A survey assessing audiology practice patterns was created using a Research Electronic Data Capture system hosted at the University of Miami. A link to a survey (65 questions in multiple-choice or rank-order format was distributed electronically along with a request for completion to members of the American Cochlear Implant Alliance and to the Institute for Cochlear Implant Training forum. Responses were collected from January 17 to June 4, 2018. Participation was limited to audiologists who evaluate adult CI candidates, and respondents who do not provide adult CI care were excluded. Collected demographic information included work setting, years of experience, and highest level of education attained.

Percentages, medians, and interquartile ranges were from aggregated responses concerning hearing aid verification methods; testing methods, materials, and practices; nonauditory factors that might affect CI candidacy; audiology practice patterns; and expanded indications for CIs.

Anonymized surveys were returned by 99 respondents; because surveys were available electronically, the number of audiologists who viewed the survey but did not respond was not available. Seven respondents identified themselves as pediatric specialists and were excluded, resulting in a total of 92 surveys available for analysis (denominators vary because respondents could complete the survey without answering all questions). Seventy percent of respondents (51 of 72) were doctors of audiology, and nearly 50% (33 of 74) were employed at universities and academic centers performing more than 50 CIs per year. When assessing adult candidacy for implant, most respondents reported using test materials from the Minimum Speech Test Battery: 96% (51 of 53), using AzBio sentences in quiet; 89% (47 of 53), AzBio sentences in noise; and 100% (53 of 53), the consonant-vowel nucleus-consonant, monosyllabic words test. However, these tests were applied inconsistently, with 39 of 53 respondents (74%) reporting use of a sound pressure level scale and the other 14 (26%) a hearing level scale at various decibel levels, and with some using a single signal-to-noise ratio and others using multiple ratios for sound-in-noise tests. Respondents' definitions of the best aided listening condition for assessing implant candidates also varied widely. Among the nonauditory factors ranked most important for assessing CI candidacy were patient's level of cognition and expectations of CI; yet, few respondents reported including cognitive or psychological tests in the assessment protocol.

Findings of this study reveal considerable variability in preoperative testing methods and practices across health care professionals assessing adult candidates for CI. This lack of standardization in the delivery of care may increase the risk for health care inequities, specifically in access to care for adults with clinically significant hearing loss.