Incidence of adverse drug reactions among elderly patients: A systematic review and meta-analysis

Abstract

Background: Several studies suggest that adverse drug reactions (ADRs) are commonly seen among hospitalized elderly and found common causes of hospital admission leading to substantial morbidity and mortality among elderly. However, no meta-analysis was conducted till date to estimate the overall incidence of ADRs among elderly. Objectives: To estimate the overall incidence of ADRs in elderly patients, incidence of ADRs in elderly in different health-care settings, incidence of serious ADRs in elderly patients, and the continent-wise incidence of ADRs in elderly patients. Design: Meta-analysis and systematic review. Methodology: Studies were identified through searching different databases such as MEDLINE, Cochrane Database of Systematic Reviews, Google Scholar, Clinical Key, and Scopus (published from 1980 to October, 2015) and by hand searching the reputed journals on geriatrics and gerontology and references of the included articles. Original peer-reviewed research articles published in English, defined ADRs according to the WHO's or similar definition and assessed the incidence of ADRs in elderly or having sufficient raw data to determine the incidence were included. Disease- or treatment-specific studies were excluded. Before meta-analysis, the studies were evaluated for heterogeneity using Chi-square and I2 statistics. The overall incidence of ADRs among the elderly with 95% confidence interval (CI) was determined using a random-effects model (DerSimonian and Laird method). Subgroup analyses were performed based on study settings and continent where the studies conducted. All the analyses were carried out using Review Manager (RevMan, version: 5.3) software. Results: Of the 5747 articles retrieved, only 56 and 54 articles were included for systematic review and meta-analysis, respectively. The overall incidence (95% CI) of ADRs among elderly population was 12.94%. The health-care setting-wise overall incidences of ADRs in the elderly were 17.53%, 19.54%, and 6.92% in inpatients, outpatients, and patients hospitalized due to ADRs, respectively. The continent-wise overall incidences of ADRs in elderly were 12.15%, 22.94%, 12.34%, and 18.76% in Asia, Australia, Europe, and USA, respectively. Electrolyte disorders and skin rashes were the common manifestations of the drugs. Cardiovascular drugs and NSAIDs were the most common causative drugs for the ADRs among elderly. Polypharmacy was the major risk factor for ADRs in elderly population, irrespective of the type of health-care settings and continents. Conclusions: The incidence of ADRs in the elderly was higher and is a significant health-care burden in the elderly. Appropriate prescribing, proper compliance, and monitoring for ADRs are needed to decrease the incidence of ADRs in elderly patients.

Keywords

• adverse drug reactions
• elderly
• systematic review and meta-analysis