Risk of anticholinergic burden in adults with intellectual disabilities: a Scottish retrospective cohort study of n = 17 220

A study on prescriptions contributing to the risk of high anticholinergic burden in adults with intellectual disabilities: retrospective record linkage study

BACKGROUND

People with intellectual disabilities may face a disproportionate risk of experiencing high anticholinergic burden, and its negative sequalae, from a range of medications, and at younger ages than the general population, but there has been little previous study. Our aim was to determine the source of anticholinergic burden from prescribed medication.

METHODS

Retrospective matched observational study using record linkage. Adults with (n = 4,305), and without (n = 12,915), intellectual disabilities matched by age-, sex- and neighbourhood deprivation. The main outcome measure was the prescription of long-term (approximately 12 months use) anticholinergic medications overall (classified according to the Anticholinergic Risk Scale [ARS]), by drug class, individual drugs, and polypharmacy.

RESULTS

Adults with n = 1,654 (38.4%), and without n = 3,047 (23.6%), intellectual disabilities were prescribed medications long-term with anticholinergic effects. Of those on such drugs, adults with intellectual disabilities were most likely to be on central nervous system (62.6%), gastrointestinal (46.7%), and cardiovascular (28.4%) medications. They were prescribed more central nervous system, gynaecological/urinary tract, musculoskeletal, and respiratory medications, and less cardiovascular, infection, and endocrine medications than their matched comparators. Regardless of age, sex, or neighbourhood deprivation, adults with intellectual disabilities had greater odds of being prescribed antipsychotics (OR = 5.37 [4.40-6.57], p < 0.001), antiepileptics (OR = 2.57 [2.22-2.99], p < 0.001), and anxiolytics/hypnotics (OR = 1.28 [1.06-1.56], p = 0.012). Compared to the general population, adults with intellectual disabilities were more likely to be exposed to overall anticholinergic polypharmacy (OR = 1.48 [1.33-1.66], p < 0.001), and to psychotropic polypharmacy (OR = 2.79 [2.41-3.23], p < 0.001).

CONCLUSIONS

Adults with intellectual disabilities are exposed to a greater risk of having very high anticholinergic burden through polypharmacy from several classes of medications, which may be prescribed by several different prescribers. There is a need for evidence-based recommendations specifically about people with intellectual disabilities with multiple physical and mental ill-health conditions to optimise medication use, reduce inappropriate prescribing and adverse anticholinergic effects.

The adverse effects of long-term exposure to anticholinergics among people with intellectual disabilities: a scoping review

Background: Older adults with intellectual disability are exposed to a higher anticholinergic burden compared to general older adults. This is due to a higher rate of both mental and neurological disorders among people with intellectual disability. The use of medications with a high anticholinergic burden is associated with adverse effects including daytime dozing, constipation and higher dependence level in the Barthel index for measuring activities of daily living. This scoping review aims to map and examine the existing research on physical and cognitive adverse effects associated with the long-term impact of anticholinergics among people with intellectual disabilities. Methods: The search was conducted in: PubMed, Cochrane library, EMBASE, Medline, Science Direct, CINAHL Complete and PsycINFO. Preliminary studies, grey literature, and conference papers were searched in related electronic databases. The search terms included terms related to ‘anticholinergic’, ‘long-term exposure’, ‘intellectual disability’ and ‘adverse drug reaction’ with Boolean operator ‘and’. Studies with at least three months’ exposure to anticholinergics were included. The search was restricted to research papers on people with intellectual disability aged 40 or over and publication in the English language only. Initially, it was conducted in May and June 2021 and covered the publication period between 1970 and 2021. It was re-run in October 2021. Results: The conducted search provided 509 records of publications and grey literature. Duplicates were removed using EndNote 20 and resulted in 432 remaining records. Then, 426 further records were excluded because they were deemed irrelevant, or non-longitudinal studies or conducted on different populations. Only six full articles were retrieved to assess their eligibility and all were excluded due to different study populations. This resulted in no studies meeting the stated inclusion criteria. Conclusions: Further research is urgently required to examine the long-term adverse effects associated with higher anticholinergic scores among older people with intellectual disability.

Rating scales to measure adverse effects of medications in people with intellectual disability: a scoping review

Purpose

Intellectual disability (ID) is a chronic neurodevelopmental condition characterised by limitations in intelligence and adaptive skills with an onset prior to the age of 18 years. People with ID have complex healthcare needs and are more likely than the general population to experience multiple comorbidities and polypharmacy, with subsequent increased risk of adverse medication effects. The aim of this scoping review is to characterise rating scales used to measure adverse effects of medication in people with ID.

Methods

Four online databases (PsycINFO, Medline, Web of Science and OpenGrey) were searched in April 2020. Studies were assessed for inclusion against pre-specified eligibility criteria. Reference lists of included studies were hand searched. Data extraction was carried out by two independent reviewers and key findings were tabulated for consideration. Studies were assessed for quality using the Mixed Methods Appraisal Tool.

Results

The search resulted in 512 unique records, of which fifteen met the inclusion criteria. Fourteen scales were identified. All scales assessed adverse effects of psychotropics only. Of the scales, only one, the Matson Evaluation of Drug Side Effects, which focuses on psychotropic medications, was originally developed for use in a population with ID.

Conclusion

The Matson Evaluation of Drug Side Effects scale appears to be the most reliable and well-researched scale in people with ID. However, a scale which measures adverse effects across multiple medication classes would be valuable for use in this population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00228-022-03375-2.