Effectiveness of unilateral cochlear implantation in people over 60 years

Hearing loss is highly prevalent among older adults, affecting their quality of life. The aim of this study was to evaluate the audiological effectiveness of unilateral cochlear implantation (CI) in individuals over 60 years of age and to identify clinical and demographic factors influencing outcomes.

A single-center, longitudinal, observational, retrospective cohort study was conducted at a tertiary care hospital. Pure-tone average (PTA) thresholds and speech intelligibility (speech audiometry) were analyzed, complemented with the SSQ-12 and HISQUI-19 sound quality questionnaires. Non-parametric tests (Mann-Whitney, Kruskal-Wallis) were applied in the absence of normality, as well as Spearman's rho correlation and linear regression to examine associations between clinical and demographic variables and audiological outcomes.

A cohort of 278 cochlear implant recipients aged 60 years or older was assessed. The final sample included 99 participants (71 implanted at ≥ 60 years after stratified random sampling; 28 implanted between 55-59 years). The mean implantation age was 67.7 ± 5.8 years. The mean postoperative PTA was 37.65 ± 10.71 dB, with a functional gain of 63.6 dB compared to preoperative levels. Mean speech intelligibility reached 53 ± 24.57%. Although initial associations suggested that younger implantation age and shorter duration of auditory deprivation correlated with better audiological outcomes, subsequent regression analyses did not confirm a statistically significant independent association for these variables. Non-native Spanish language use was identified as a significant negative predictor of intelligibility. Poorer thresholds were associated with family history of hearing loss (p = 0.01) and lower body mass index (p = 0.005). Among complications (8.4%), the most relevant were three CI explantation/reimplantation cases (3%).

Unilateral cochlear implantation is highly effective in adults over 60 years, restoring functional hearing. Overall results are comparable to younger populations, supporting the indication of cochlear implantation in older adults. Speech intelligibility showed high interindividual variability, partially explained by non-native Spanish language use. Regression analysis showed that neither implantation age nor duration of auditory deprivation had an independent association with outcomes in this cohort, and therefore should not be considered contraindications for CI. The finding that 50.5% of cases had a family history of hearing loss suggests the need to expand genetic testing in adult CI candidates. The low complication rate (8.4%) confirms the safety of cochlear implantation.