Evidence for the expansion of adult cochlear implant candidacy

Abstract

Objectives: The primary objective of this study was to determine whether a revision and/or expansion of current audiologic cochlear implant candidacy criteria is warranted.

Design: The study design was a retrospective review of postoperative speech perception performance for 22 adult cochlear implant recipients who demonstrated preoperative Consonant Nucleus Consonant word recognition scores of 30% or higher in the best-aided condition. This criterion was chosen to exceed that specified by the North American clinical trial of the Nucleus Freedom cochlear implant system.

Results: The mean preoperative best-aided monosyllabic word score for the 22 patients was 41% correct. The degree of postoperative benefit for the best postoperative condition (electric only or bimodal) ranged from 10 to 68 percentage points with a mean benefit of 27 percentage points for the electric-only condition and 40 percentage points for the bimodal condition. Statistical analyses revealed highly significant differences between preoperative-aided, implant-only, and bimodal performance on Consonant Nucleus Consonant monosyllabic word recognition performance. That is, both postoperative scores--electric only and bimodal--were significantly different from one another and from the preoperative best-aided performance.

Conclusions: The current results suggest that a large-scale reassessment of manufacturer and Medicare preoperative audiologic candidacy criteria for adults is warranted to allow more hearing-impaired individuals to take advantage of the benefits offered by cochlear implantation.

Fig. 1

Individual and mean performance for Consonant Nucleus Consonant monosyllabic words. The shaded bars represent the best-aided, preoperative score, the hatched bars represent the electric-only score, and the filled bars represent the bimodal score. The horizontal dashed line marks 30% correct performance, which was the binaural-aided preoperative criterion for inclusion in the study. Error bars represent ±2 SE measurements.

Fig. 2

Individual and mean performance for Consonant Nucleus Consonant monosyllabic words for the nine subjects for whom preimplant and postimplant scores were obtained for the implanted ear. The shaded and filled bars represent the preimplant and postimplant scores, respectively. Error bars represent ±2 SE measurements.

Fig. 3

Panel A displays postoperative Consonant Nucleus Consonant word scores (in percent correct) for the electric (E)-only condition as a function of the preoperative, implant ear pure-tone average, in dB HL, for frequencies 250, 500, and 1000 Hz. Panel B displays postoperative Consonant Nucleus Consonant word scores for the bimodal condition as function of the preoperative, nonimplanted ear pure-tone average at 250, 500, and 1000 Hz.