Incorporating ceiling effects during analysis of speech perception data from a paediatric cochlear implant cohort

Objective: To compare speech perception between children with a different age at cochlear implantation. Design: We evaluated speech perception by comparing consonant–vowel–consonant (auditory) (CVC(A)) scores at five-year follow-up of children implanted between 1997 and 2010. The proportion of children from each age-at-implantation group reaching the 95%CI of CVC(A) ceiling scores (>95%) was calculated to identify speech perception differences masked by ceiling effects. Study sample: 54 children implanted between 8 and 36 months. Results: Although ceiling effects occurred, a CVC(A) score difference between age-at-implantation groups was confirmed (H (4) = 30.36; p < 0.001). Outperformance of early (<18 months) compared to later implanted children was demonstrated (p <0.001). A larger proportion of children implanted before 13 months compared to children implanted between 13 and 18 months reached ceiling scores. Logistic regression confirmed that age at implantation predicted whether a child reached a ceiling score. Conclusions: Ceiling effects can mask thorough delineation of speech perception. However, this study showed long-term speech perception outperformance of early implanted children (<18 months) either including or not accounting for ceiling effects during analysis. Development of long-term assessment tools not affected by ceiling effects is essential to maintain adequate assessment of young implanted infants.