Adverse-Drug-Reaction-Related Hospitalisations in Developed and Developing Countries: A Review of Prevalence and Contributing Factors.

Adverse drug reactions (ADRs) are one of the leading causes of hospital admissions and morbidity in developed countries and represent a substantial burden on healthcare delivery systems. However, there is little data available from low- and middle-income countries. This review compares the prevalence and characteristics of ADR-related hospitalisations in adults in developed and developing countries, including the mortality, severity and preventability associated with these events, commonly implicated drugs and contributing factors. A literature search was conducted via PubMed, Scopus, Web of Science, Embase, ProQuest and Google Scholar to find articles published in English from 2000 to 2015. Relevant observational studies were included. The median (with interquartile range [IQR]) prevalence of ADR-related hospitalisation in developed and developing countries was 6.3 % (3.3-11.0) and 5.5 % (1.1-16.9), respectively. The median proportions of preventable ADRs in developed and developing countries were 71.7 % (62.3-80.0) and 59.6 % (51.5-79.6), respectively. Similarly, the median proportions of ADRs resulting in mortality in developed and developing countries were 1.7 % (0.7-4.8) and 1.8 % (0.8-8.0), respectively. Commonly implicated drugs in both settings were antithrombotic, non-steroidal anti-inflammatory and cardiovascular drugs. Older age, female gender, number of medications, renal impairment and heart failure were reported to be associated with an increased risk for ADR-related hospitalisation in both settings while HIV/AIDS was implicated in developing countries only. The majority of ADRs were preventable in both settings, highlighting the importance of improving medication use, particularly in vulnerable patient groups such as the elderly, patients with multiple comorbidities and, in developing countries, patients with HIV/AIDS.