Avoidable hospitalizations due to adverse drug reactions in an acute geriatric unit. Analysis of 3,292 patients

Abstract

ObjectiveTo determine prevalence of admissions due to an adverse drug reaction (ADR) and determine whether or not admission was avoidable, and what drugs and risk factors were implicated. DesignCross-sectional observational study. Study sampleAll patients hospitalized in an acute geriatric unit during the period January 2001 to December 2010 were studied. MeasurementTo determine whether admissions were due to ADR, we used the World Health Organization-Uppsala Monitoring Centre criteria and the Naranjo scale. Beers criteria were used to detect potentially inappropriate medication. ResultsA total of 3292 patients (mean age 84.7 years, 60.1% women) were studied. Of these, 197 (6%) were admissions for ADR and nearly three quarters (76.4%, 152 cases) were considered avoidable admissions. The five most frequent drugs associated with admissions for ADR were digoxin, nonsteroidal anti-inflammatory drugs, benzodiazepines, diuretics and antibiotics. Independent risk factors for admissions for ADR were being female (OR 1.84; 95% CI: 1.30–2.61), inappropriate medication according to Beers criteria (OR 4.20; 95% CI: 2.90–6.03), polypharmacy (>5 drugs) (OR 1.50; 95% CI: 1.04–2.13), glomerular filtration rate<30mL/min (OR 3; 95% CI: 2.12–4.23) and sedative use (OR 1.40; 95% CI: 1–1.91). ConclusionADR were responsible for 6% of admissions to an acute geriatric unit, and over 75% of these admissions were considered avoidable. Associated risk factors were being female, inappropriate medication, polypharmacy, renal insufficiency and sedative use.