Prevalence of adverse drug reactions associated with emergency department visits and risk factors for hospitalization.

OBJECTIVE

Adverse drug reactions increase morbidity and mortality, prolong hospital stay and increase healthcare costs. The primary objective of this study was to determine the prevalence of emergency department visits for adverse drug reactions and to describe their characteristics. The secondary objective was to determine the predictor variables of hospitalization for adverse drug reactions associated with emergency department visits.

METHODS

Observational and retrospective study of adverse drug reactions registered in an emergency department, carried out from November 15th to December 15th, 2021. The demographic and clinical characteristics of the patients, the drugs involved and the adverse drug reactions were described. Logistic regression was performed to identify factors related to hospitalization for adverse drug reactions.

RESULTS

10,799 patients visited the ED and 216 (2%) patients with adverse drug reactions were included. The mean age was 70 ± 17.5 (18-98) years and 47.7% of the patients were male. A total of 54.6% of patients required hospitalization and 1.6% died from adverse drug reactions. The total number of drugs involved was 315 with 149 different drugs. The pharmacological group corresponding to the nervous system constituted the most representative group (n = 81). High-risk medications, such as antithrombotic agents (n = 53), were the subgroup of medications that caused the most emergency department visits and hospitalization. Acenocumarol (n = 20) was the main drug involved. Gastrointestinal (n = 62) disorders were the most common. Diarrhea (n = 16) was the most frequent adverse drug reaction, while gastrointestinal bleeding (n = 13) caused the highest number of hospitalizations. Charlson comorbidity index behaved as an independent risk factor for hospitalization (aOR 3.24; 95% CI: 1.47-7.13; p=0.003, in Charlson comorbidity index 4-6, and aOR 20.07; 95% CI: 6.87-58.64; p = 0.000, in Charlson comorbidity index ≥ 10).

CONCLUSIONS

The prevalence of emergency department visits for adverse drug reactions continues to be a non-negligible health problem. High-risk drugs such as antithrombotic agents were the main therapeutic subgroup involved. Charlson comorbidity index was an independent factor in hospitalization, while gastrointestinal bleeding was the adverse drug reaction with the highest number of hospital admissions.