Adverse Drug reactions in an Ageing PopulaTion (ADAPT) study protocol: a cross-sectional and prospective cohort study of hospital admissions related to adverse drug reactions in older patients.

INTRODUCTION: Older people experience greater morbidity with a corresponding increase in medication use resulting in a potentially higher risk of adverse drug reactions (ADRs). The aim of this study is to determine the prevalence and characteristics of ADR-related hospital admissions among older patients (≥65 years) and their associated health and cost outcomes.

METHODS AND ANALYSIS: The proposed study will include a cross-sectional study of ADR prevalence in all patients aged ≥65 years admitted acutely to a large tertiary referral hospital in Ireland over a 9-month period (2016-2017) and a prospective cohort study of patient-reported health outcomes and costs associated with ADR-related hospital admissions. All acute medical admissions will be screened for a suspected ADR-related hospital admission. A number of validated algorithms will be applied to assess the type, causative medications, preventability and severity of each ADR. ADRs will be determined, using a consensus method, by an expert panel. Patients who provide consent will be followed up 3 months post-discharge to establish patient-reported health outcomes (health service use, health-related quality of life, adherence) and costs associated with ADR-related hospital admissions. A random sample of patients admitted to hospital without a suspected ADR will be invited to take part in the study as a control group.

ETHICS AND DISSEMINATION: Ethical approval was obtained from Beaumont Hospital Ethics Committee. Findings will be disseminated through presentations and peer-reviewed publications.