Adverse drug reactions, multimorbidity and polypharmacy: a prospective analysis of 1 month of medical admissions

Osanlou, Rostam, Walker, Lauren ORCID: 0000-0002-3827-4387, Hughes, Dyfrig A ORCID: 0000-0001-8247-7459, Burnside, Girvan ORCID: 0000-0001-7398-1346 and Pirmohamed, Munir ORCID: 0000-0002-7534-7266
(2022) Adverse drug reactions, multimorbidity and polypharmacy: a prospective analysis of 1 month of medical admissions. BMJ OPEN, 12 (7). e055551-.

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<h4>Objective</h4>To ascertain the burden and associated cost of adverse drug reactions (ADRs), polypharmacy and multimorbidity through a prospective analysis of all medical admissions to a large university teaching hospital over a 1-month period.<h4>Design</h4>Prospective observational study.<h4>Setting</h4>Liverpool University Hospital Foundation National Health Service (NHS) Trust, England.<h4>Participants</h4>All medical admissions with greater than 24-hour stay over a 1-month period.<h4>Main outcome measures</h4>Prevalence of admissions due to an ADR and associated mortality, prevalence and association of multimorbidity and polypharmacy with ADRs, and estimated local financial cost of admissions where an ADR was a contributing or main reason for admission with projected costs for NHS in England.<h4>Results</h4>There were 218 identified patient admissions with an ADR giving a prevalence of 18.4%. The majority of these (90.4%) were ADRs that directly resulted in or contributed to admission. ADRs thus accounted for 16.5% of total admissions. Those with an ADR were on average taking more medicines (10.5 vs 7.8, p<0.01) and had more comorbidities than those without an ADR (6.1 vs 5.2, p<0.01). Drugs most commonly implicated were diuretics, steroid inhalers, anticoagulants and antiplatelets, proton pump inhibitors, chemotherapeutic agents and antihypertensives. 40.4% of ADRs were classified avoidable or possibly avoidable. The mortality rate due to an ADR was 0.34%. The average length of stay for those with an ADR was 6 days. Direct 1-month cost to the Trust from ADR admissions was £490 716. Extrapolated nationally, the projected annual cost to the NHS in England is 2.21 billion.<h4>Conclusion</h4>The local prevalence of admission and mortality from ADRs is higher than previously reported. Important factors that could be contributing to this include polypharmacy and multimorbidity. ADRs place a significant burden on patients and healthcare services with associated financial implications. Reducing inappropriate polypharmacy should be a major aim for preventing ADRs.

Item Type: Article
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Clinical Directorate
Faculty of Health and Life Sciences > Institute of Systems, Molecular and Integrative Biology
Depositing User: Symplectic Admin
Date Deposited: 13 Jul 2022 13:51
Last Modified: 18 Jan 2023 20:56
DOI: 10.1136/bmjopen-2021-055551
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