Exploring factors that affect the age of cochlear implantation in children

Objective

Early access to sound through early cochlear implantation has been widely advocated for children who do not derive sufficient benefit from acoustic amplification. Early identification through newborn hearing screening should lead to earlier intervention including earlier cochlear implantation when appropriate. Despite earlier diagnosis and the trend towards early implantation, many children are still implanted well into their preschool years. The purpose of this study was to examine the factors that affected late cochlear implantation in children with early onset permanent sensorineural hearing loss.

Methods

Data were examined for 43 children with cochlear implants who were part of a group of 71 children with hearing loss enrolled in a Canadian outcomes study. Eighteen (41.9%) of the 43 children were identified through newborn screening and 25 (58.1%) through medical referral to audiology. Medical chart data were examined to determine age of hearing loss diagnosis, age at cochlear implant candidacy, and age at cochlear implantation. Detailed reviews were conducted to identify the factors that resulted in implantation more than 12 months after hearing loss confirmation.

Results

The median age of diagnosis of hearing loss for all 43 children was 9.0 (IQR: 5.1, 15.8) months and a median of 9.1 (IQR: 5.6, 26.8) months elapsed between diagnosis and unilateral cochlear implantation. The median age at identification for the screened groups was 3.3 months (IQR: 1.4, 7.1) but age at implantation (median 15.8 months: IQR: 5.6, 37.1) was highly variable. Eighteen of 43 children (41.9%) received a cochlear implant more than 12 months after initial hearing loss diagnosis. For many children, diagnosis of hearing loss was not equivalent to the determination of cochlear implant candidacy. Detailed reviews of audiologic profiles and study data indicated that late implantation could be accounted for primarily by progressive hearing loss (11 children), complex medical conditions (4 children) and other miscellaneous factors (3 children).

Conclusions

This study suggests that a substantial number of children will continue to receive cochlear implants well beyond their first birthday primarily due to progressive hearing loss. In addition, other medical conditions may contribute to delayed decisions in pediatric cochlear implantation.