Objective: The benefits of cochlear implantation for children with developmental delays (DD) often are unclear. We compared cognition, adaptive behavior, familial stress, and communication in children with and without DD.
Study design: Retrospective review.
Setting: Two tertiary care pediatric hospitals.
Patients: Two hundred four children who underwent cochlear implantation assessed before and more than 1 year after implantation.
Main outcome measures: The Mullen Scales of Early Learning (MSEL), vineland adaptive behavior scales (VABS), Parental Stress Index, and Preschool Language Scale.
Results: We developed a specific definition of DD for hearing-impaired children based upon diagnostic and statistical manual of mental disorders, fourth edition, criteria for mental retardation; 60 children met the criteria for DD, and 144 children did not. Before implantation, multiple linear regression demonstrated that children with DD had lower scores in every domain of the MSEL and VABS (p < 0.05), but no differences in any domains of the parental stress index and preschool language scale (p > 0.1) compared with children without DD. After implantation, children without DD demonstrated significant improvements in intelligence as measured by the MSEL and age-appropriate improvements in adaptive behavior as evaluated by the VABS, and their familial stress levels were not increased after cochlear implantation. In contrast, children with DD underwent implantation at a later age and demonstrated less comprehensive developmental improvements after cochlear implantation and higher stress levels. However, when the age differences were taken into account using multiple linear regression analyses, the differences between the 2 cohorts were reduced.
Conclusion: These data indicate that our definition of DD is a reliable method of stratifying deaf children. Although children with DD have a normal developmental rate of adaptive behavior after cochlear implantation, their developmental rate of intelligence is lower, and they have higher stress levels than children without DD. However, our data suggest that if children with DD could be implanted as early as children without DD, their intelligence and stress outcomes would be improved.