Abstract:
OBJECTIVE : To identify which preoperative patient characteristics influence sequential
bilateral cochlear implantation performance and to create a statistical model that
predicts benefit.
DESIGN : Multicentre retrospective cohort study.
SETTING : All patients were operated in four academic teaching hospitals in Perth,
Australia, and followed up by audiologists of the Ear Science Institute Australia.
PARTICIPANTS : A total of 92 postlingually deafened adult patients who had undergone
sequential cochlear implantations between 19 June 1990 and 14 March 2016 were
included. Patients were excluded if the 12‐month follow‐up consonant‐nucleus‐consonant
(CNC) phoneme score was missing.
MAIN OUTCOME MEASURE : The effect of 18 preoperative factors on the CNC phoneme
score in quiet (at 65 dB SPL) with the second cochlear implant (CI2) one year
after implantation.
RESULTS : Two factors were positively correlated to speech understanding with CI2:
Wearing a hearing aid (HA) before receiving CI2 (r = 0.46, P = 0.00) and the maximum
CNC phoneme score with the first CI (CI1) (r = 0.21, P = 0.05). Two factors
were negatively correlated: the length of hearing loss before CI2 in the second
implanted ear (r = −0.25, P = 0.02) and preoperative pure tone average (PTA) (0.5,
1, 2 kHz) before CI2 in the second implanted ear (r = −0.27, P = 0.01). The following
model could be created: predicted CNC phoneme score with CI2
(%) = 16 + (44 * HA use before CI2 (yes)) − (0.22 * length of hearing loss before CI2 (years)) + (0.23 * CNC phoneme score with CI1 (%)). Because the effect of
HA use before implantation played such a major role, we also created a model
after exclusion of the HA factor: Predicted CNC phoneme score with CI2 (%) = 82
− (0.17 * length of hearing loss before CI2 (years)) − (0.27 * PTA in second
implanted ear before CI2 (0.5, 1, 2 kHz)) + (0.20 * CNC phoneme score with CI1
(%)).
CONCLUSION : Advanced age or a long interval between implantations does not necessarily
lead to poor CI2 results. Patients who are successful HA users before CI2,
who have a low PTA before CI2, a high CNC phoneme score with CI1 and a limited
length of hearing loss before CI2, are likely to be successful CI2 recipients.
