Hospital admissions due to adverse drug reactions in the elderly. A meta-analysis.

INTRODUCTION: It is currently admitted that adverse drug reactions (ADRs) account for a great burden of disease. Of particular concern are ADR-induced hospital admissions, particularly in the elderly; they receive most of the medications and they are the most prone to develop ADRs. Therefore, our aim was to carry out a study of ADR-induced hospital admissions focused on the elderly population.

METHODS: For the purpose, a systematic review and meta-analysis was performed of those studies addressing ADR-induced hospital admissions in patients over 60 years of age. A computerized search of the literature was carried out in the main databases. The search spans from 1988 to 2015. A pooled prevalence figure was calculated with 95% CIs; heterogeneity was also explored.

RESULTS: The final number of selected articles was 42; all of them were published between January 1988 and August 2015. The overall average percentage of hospital admissions was 8.7% (95% CI, 7.6-9.8%). NSAIDs are one of the medication classes more frequently related to these admissions (percentages range from 2.3 to 33.3%). Inappropriate medication as a risk factor was studied in nine studies, four found a statistically significant relationship between those medications and hospital admissions.

CONCLUSIONS: Circa one in ten hospital admissions of older patients are due to ADRs. A great burden of disease is due to a few and identifiable medication classes; in most of the cases, the reactions are well known and probably preventable. A sense of purpose and determination is needed by health authorities to face this problem. Doctors, on their part, should be aware when prescribing some specific identifiable medications to these patients.

KEY POINTS: 1. One in ten hospital admissions in older patients are due to ADRs; NSAIDs are the medications the most related with these admissions, followed by other common medications used in patients of this age, such as beta-blockers. 2. A great burden of disease is due to medications that are intended to cure or alleviate disease; this burden of disease is not only painful for the patients but also costly. 3. Identified risk factors are particular medication classes and polymedication. In most of the cases, reactions are probably preventable.