[Hospital readmission induced by adverse drug reaction: a pilot study in a post-emergency unit of a French university hospital]

Purpose: Adverse Drug Reactions (ADRs) leading to hospital admission was estimated to 3.6 to 21.7%. Despite its importance in terms of patients care, readmission to hospital due to ADRs remains poorly documented. The aim of our study was to investigate the rate and main characteristics of readmission for ADRs.

Methods: We undertook a retrospective study during two years (2011-2012) in the post-emergency unit of Toulouse university hospital (south western, France). We selected all unplanned hospitalization for acute disease and included all cases of patients admitted twice fold or more for ADRs. Characteristics of drug-induced ADRs were assessed according to appropriate use or not.

Results: Out of the 197 readmitted patients, 71 was related to ADRs (3.6%) corresponding to 17.8‰ patients-year. Mean age was 82.3 years and 67% were women. The most frequent ADRs found were vascular (n=41, 18.4%), gastro-intestinal (n=28, 12.6%), cardiac (n=28, 12.6%), neurologic (n=26, 11.7%), metabolic (n=26, 10.3%) and psychiatric (n=24, 9.9%). The drugs mainly involved were psychoactive, cardiovascular, digestive or antithrombotic agents. The context of occurrence of ADRs was related to inappropriate drug prescription in 56% of cases. A total of 24 patients were admitted twice for the same ADR and 2 others three times. For 22 patients (30.9%), the same drugs were involved.

Conclusion: Our data show hospital readmission was due to ADRs in 3.6% of cases. In 1.1% of cases, the same couple "drug-ADR" was involved. Furthermore, in 56% of cases, repeated admissions are related to an inappropriate drug prescription.