Prevalence and incidence of myocardial infarction and cerebrovascular accident in ageing persons with intellectual disability

Background: Epidemiological information on age-related cardiovascular disease in people with intellectual disability (ID) is scarce and inconclusive. We compared prevalence and incidence of cerebrovascular accident and myocardial infarction over age 50 in a residential population with ID to that in a general practice population.
Method: A retrospective descriptive study was conducted, based on medical records of 510 persons with ID and 823 general practice patients, aged 50 years and over.
Results: Lifetime prevalences after age 50 were similar in both populations: 5.7% (95% CI 4.0-8.1%) in persons with ID and 4.4% (95% CI 3.1-6.0%) in the general population (Pearson chi-square 1.17, P=0.279). Incidence per gender was similar between cohorts (men P=0.86, women P=0.36). There was no difference in incidence rates between the ID and control groups [relative risk=1.5 (95% CI 0.9-2.4)].
Conclusion: Prevalence and incidence of myocardial infarction and cerebrovascular accident in ageing persons with ID do not appear different from those in the general population. It has to be taken into account that underdiagnosis and selection bias towards a more disabled group may have lead to underestimation of age-related cardiovascular morbidity, and the higher age and underrepresentation of Down syndrome to overestimation.