The Effect of Comorbidities on Cochlear Implantation Outcomes in Adults under 60

Introduction: Prior studies have demonstrated that comorbid conditions can negatively impact cochlear implantation (CI) outcomes in elderly patients, but few have examined how comorbidities affect younger adult CI recipients. This study examines the relationship between comorbidities and CI outcomes in adults under 60 years old.

We reviewed all CI recipients between 20 and 60 years old from 2015 to 2019 at a tertiary academic medical center. Patient data were collected including comorbidities, demographics, etiology, and length of deafness (LOD). Patients' Charlson Comorbidity Index (CCI) was calculated. The primary outcome was speech perception scores at 1 year on the consonant-nucleus-consonant (CNC) word test.

There were 118 patients who underwent CI (20-29 years [15%], 30-39 years [22%], 40-49 years [21%], 50-60 years [42%]), averaging 1.8 comorbidities. Mean LOD was 19.7 years, and most etiologies were unknown (53.4%). 34% had no comorbidities, and the most frequent comorbidities were hypertension (14%), asthma (10%), anxiety (8%), acoustic neuroma (8%), and arthritis (7%). Comorbidity frequency was similar across ages, but cardiovascular comorbidities varied by patient decade (50-60 years: 41% vs. 20-49 years: 12-22%, p = 0.004). Compared to studies on elderly CI outcomes, our cohort had fewer comorbidities with reduced cardiac events and neurological conditions. We did not find differences in 1-year CNC scores or complications based on the number of comorbidities or any single comorbidity. However, there was a difference in individual improvement in CNC word scores by age group (p = 0.024). Patients' CCI did not correlate to post-op scores.

Subjects showed improved speech understanding post-CI. The number and type of comorbidities were not meaningful predictors of 1-year speech perception scores, suggesting adult CI users under 60 years with comorbidities can expect comparable outcomes to those without comorbidities.