Consultant Mayo Clinic Children's Center Rochester, Minnesota, United States
Background: Formal hearing assessments in patients with autism spectrum disorder (ASD) is complex, possibly leading to delayed identification of hearing loss (HL) in this subgroup of patients. Research suggests up to 3.5% of people with ASD have HL, with sensorineural HL being the most common type in this ASD population. Objective: We aimed to characterize the auditory profile of research-identified cases of ASD (ASD-R) in a population-based birth cohort. Design/Methods: ASD-R cases were identified from 31,220 subjects in a population-based birth cohort based on retrospective chart review for DSM-IV-TR autistic disorder, Asperger Disorder, and pervasive developmental disorder not otherwise specified criteria, encompassing current DSM-5 ASD symptomatology. ASD-R cases were considered clinically diagnosed ASD if an ASD clinical diagnosis was present in the medical record. HL diagnosis codes were included if the HL diagnosis occurred prior to age 19 and were then classified as conductive or sensorineural HL based on further chart review, including available clinical notes and audiometry data. Presence of clinical ASD diagnosis was compared to presence of ASD-R diagnosis in subjects with HL. Differences in odds of ASD clinical diagnosis were tested between hearing loss groups with logistic regression. Results: 1,019 patients with ASD-R were included in final analysis, with 220 of those subjects clinically diagnosed with ASD. 22% of ASD-R (N = 225) had HL overall, 81% (N = 182) with conductive HL and 19% (N = 42) with sensorineural HL. 26% of clinically diagnosed ASD subjects (N = 58) had a HL diagnosis. The mean of years from meeting ASD-R criteria to HL diagnosis was 1.8 years, with standard deviation of 5.2 years. Of patients with hearing loss, 32% had HL first and 68% met research criteria for ASD first. Subjects with HL were not estimated to have different odds of an ASD clinical diagnosis compared to subjects without HL (OR: 1.36, CI: 0.96-1.91, p = 0.084). Cases with conductive HL were not estimated to have different odds of ASD clinical diagnosis compared to those with sensorineural HL (OR: 1.15, CI: 0.52-2.51, p = 0.733).
Conclusion(s): Compared to prior studies, we found a higher rate of hearing loss in ASD, as well as more predominant conductive hearing loss in this ASD population utilizing a population-based birth cohort. Subjects more commonly met research criteria for autism prior to being diagnosed with hearing loss. We confirm the need for targeted developmental and audiologic assessment for this complex sub-population with co-occurring ASD and HL.
