Data-Driven Multiparameter Predictive Analysis of Cochlear Implant Rehabilitation Outcomes

Objective: This study analyzes intersections between preoperative predictors of postcochlear implant (CI) hearing outcomes to address the gap in counseling CI candidates on postoperative hearing expectations beyond binary candidacy criteria. Study design: Retrospective cohort study. Setting: Tertiary academic medical center and a third-party CI database. Methods: Preoperative audiometric measures included word recognition score (WRS) and pure-tone average (PTA) for the unimplanted contralateral ear (CE) and implanted ear (IE). Postoperative WRS assessments extended to 500 days postsurgery, with the ~6-month mark as the primary outcome time point. Treatment success was defined as a postoperative WRS≥60% or clinically meaningful improvement (Δ WRS ≥20%) for individuals with preoperative WRS≥30%. Statistical analyses included heatmaps and Kaplan-Meier plots to assess relationships between preoperative variables and time to treatment success. Results: Both CE and IE audiometric status demonstrated comparable predictive ability for CI outcomes when using the WRS<60% and PTA>60 criteria; however, IE status had a higher F1 score (0.27 vs. 0.069). Age was a critical modifier; patients below 60 years achieved treatment success faster than older patients (275 vs. 470 d; HR=0.41; 95% CI: 0.31-0.55, P <0.05). Patients below 60 years achieved hearing improvement at a significantly faster rate when using a pre-PTA<60 dB than a pre-PTA≥60 dB (HR=0.47, 95% CI: 0.22-0.99, P <0.05). Among older patients, those with CE WRS≥60% had a substantially higher likelihood of improvement compared with those with WRS <60% (HR=5.15; 95% CI: 3.29-8.08, P <0.05). Conclusion: Preoperative audiometric predictors of CI success vary significantly by age, with younger patients benefiting from residual hearing in the implanted ear and older patients relying on their contralateral, unimplanted ear for rehabilitation. These age-stratified patterns enable more personalized prognostic counseling about expected time to functional hearing improvement following cochlear implantation.