Comorbidities in individuals with intellectual disabilities with and without hearing loss: a prospective cohort study

Abstract Background Both intellectual disability (ID) and hearing loss (HL) are associated with a high prevalence of certain comorbidities. However, a combined analysis and overview classified according to the International Classification of Diseases, 11th Revision (ICD-11), is lacking. HL is disproportionately common among individuals with ID and often remains undetected. We evaluated: (1) which comorbidities are most common in ID; (2) how disease prevalence differs between those with and without HL; (3) whether the degree of ID or HL influences the number of additional diseases, surgeries, or medication intake. Methods This study is part of a prospective cohort study investigating effectiveness and feasibility of repeated universal hearing screenings and interventions for people with ID. We included 1,053 participants with ID (37% female, 63% male, and < 1% intersex; age range 1–90 years). Medical history assessment and on-site hearing testing were combined. Diseases were ICD-11-coded. Descriptive statistics and binary logistic regression models assessed associations between common diseases and age, sex, HL, and ID. Results Nearly all comorbidities observed in participants with HL (prevalence > 5% [ = 14]) were more frequent in participants with HL vs. without (13/14), eight showing odds ratios [OR] and 95% confidence interval [CI] > 1: visual impairment; hypertension; trisomy 21; obesity; mental, behavioural, or neurodevelopmental disorders; spinal conditions; diabetes; hypothyroidism. Logistic regression underscored associations between: (1) HL and visual impairment, trisomy 21, spinal conditions, hypothyroidism; (2) age and hypertension, obesity, diabetes; (3) female sex and trisomy 21, hypothyroidism. Epilepsy occurred similarly (OR 1.01, 95% CI: 0.65–1.56) and autism spectrum disorder (ASD) less often in the HL-subcohort (OR 0.42, 95% CI: 0.24–0.73). Trisomy 21 was 3–4 times more frequent in the HL-subcohort, showed a female preponderance and high rates of cardiovascular, metabolic, and visual diseases. Associated comorbidities (mean 2.75 vs 1.65) and multimorbidity (≥ two diseases, 63% vs. 42%) were higher in persons with HL than without, as was medication intake (mean 2.73 vs. 0.84). Conclusion In our study individuals with ID and HL showed increased comorbidity, multimorbidity, and higher medication intake than those without HL. Heightened awareness and individualised, multidisciplinary management are essential in order to ensure equitable care and prevent secondary complications.