A prospective cohort study on prevalence and healthcare utilization

BACKGROUND: People with intellectual disabilities (ID, prevalence ca. 1.04%) have an elevated risk of hearing impairments, which, if untreated, can hinder communication, cognitive development, and social participation. In a project called "HörGeist," we studied the prevalence of hearing impairments and the feasibility and utility of an outreach auditory screening, diagnosis, and intervention program for people with ID in their living and working environments. METHODS: In an age-stratified cohort study with a total of 1194 subjects, 1053 people with ID (outreach cohort, aged 1-90 years) underwent auditory screening in their living or working environment twice one year apart, and, if indicated, a diagnostic evaluation for a hearing impairment and either an intervention or a referral for outside treatment. To compare utilization, a control cohort of people with ID (141 subjects) was offered screening and auditory diagnostic testing in a clinical setting. RESULTS: Clinically relevant hearing impairments were diagnosed in 44.0% of patients in the outreach cohort; 69.8% of these impairments had not been identified previously. Cerumen obturans affecting hearing was present in 9.9% of the impairments. Approximately one-third of the subjects or their carers overestimated their hearing ability. Screening and diagnostic evaluation yielded a conclusive result in 96.7% of cases. Screening had an estimated 92.3% specificity (95% confidence interval: [89.6; 94.3]) and 96.4% sensitivity ([94.1; 97.8]). None of the subjects in the invited control cohort made use of the auditory screening program. The prevalence of hearing impairments varied depending on sex, age, and type of institution. CONCLUSION: The prevalence of hearing impairments in people with ID is high, and most cases are unrecognized. A comprehensive outreach program of auditory screening, diagnostic evaluation, and intervention for people with ID appears feasible and justified and would reach more of the affected persons than a simple invitation. It could improve their social participation as well.