Epidemiology and outcomes of geriatric patients with drug allergy

Abstract

Background: Adverse drug reactions are much more common in geriatric patients but there have been no adequate studies on the epidemiology or burden of drug allergy (DA) in the elderly. The objective is to report on the prevalence and outcomes of geriatric patients with DA labels on a prospective cohort of hospitalized patients. Method: Patients admitted to a regional hospital over a 6-month period were recruited for analysis. All patients with DA labels were prospectively followed until discharge with clinical data anonymously extracted for analyses. Patients were categorized into either geriatric (age ≥65 years) or non-geriatric (age <65 years) groups, with differences in demographics, clinical outcomes and prevalence of DA labels analyzed. Results: There were 4361 admission consisting of 3641 patients over the 6-month study period. Four-hundred-and-ninety-two patients (13.5%) had DA labels, consisting of 151 (30.7%) non-geriatric and 341 (69.3%) geriatric patients. There was no significant difference in the prevalence of DA between geriatric and non-geriatric patients (13.5% vs 15.2%, p=0.170). Significantly more patients in the geriatric group had DA to cardiovascular system (CVS) drugs (15.5% vs 4.6%, p=0.001). Patients in the geriatric group had a significantly lower rate of direct discharge from hospital (73.0% vs 88.1%, p<0.001) and required transferal to convalescent or rehabilitation care for further management. Conclusion: More than 13% of hospitalized geriatric patients carry DA labels. We identified the leading causes of DA, which were similar to the non-geriatric group. We also observed significantly more labelled allergy to CVS drugs and adverse clinical outcomes in geriatric patients with DA.