Emergency re-admissions to hospital due to adverse drug reactions within 1 year of the index admission

Abstract

Aim: The proportion of re-admissions to hospital caused by ADRs is poorly documented in the UK. The aim of this study was to evaluate the impact of ADRs on re-admission to hospital after a period as an inpatient.

Methods: One thousand patients consecutively admitted to 12 wards were included. All subsequent admissions for this cohort within 1 year of discharge from the index admission were retrospectively reviewed.

Results: Of the 1000 patients included, 403 (40.3%, 95% CI 39.1, 45.4%) were re-admitted within 1 year. Complete data were available for 290 (70.2%) re-admitted patients, with an ADR contributing to admission in 60 (20.8%, 95% CI 16.4, 25.6%) patients. Presence of an ADR in the index admission did not predict for an ADR-related re-admission (10.5% vs. 7.2%, P=0.25), or re-admission overall (47.2% vs. 41.2%, P=0.15). The implicated drug was commenced in the index admission in 33/148 (22.3%) instances, with 37/148 (25%) commenced elsewhere since the index admission. Increasing age and an index admission in a medical ward were associated with a higher incidence of re-admission ADR. The most frequent causative drugs were anti-platelets and loop diuretics, with bleeding and renal impairment the most frequent ADRs. Over half (52/91, 57.1%) of the ADRs were judged to be definitely or possibly avoidable.

Conclusions: One fifth of patients re-admitted to hospital within 1 year of discharge from their index admission are re-admitted due to an ADR. Our data highlight drug and patient groups where interventions are needed to reduce the incidence of ADRs leading to re-admission.