steroids, antibiotics, opiates/narcotics, and anticoagulants. Patients treated in urban teaching hospitals had higher rates of ADEs involving antibiotics and opiates/narcotics compared to those treated in urban nonteaching hospitals. Those treated in private, nonprofit hospitals had higher rates of most ADE causes compared to patients treated in public or private, for-profit hospitals. MRH is common after hospital discharge in older adults, but methodological inconsistencies between studies and a paucity of data on risk factors limits clear understanding of the epidemiology. There was a wide range in incidence, from 0.4% to 51.2% of participants, and 35% to 59% of harm was preventable. Medication related harm incidence within 30 days after discharge ranged from 167 to 500 events per 1,000 individuals discharged (17–51% of individuals). In the U.S., females had a higher rate of ADEs involving opiates and narcotics than males in 2011, while male patients had a higher rate of anticoagulant ADEs. Nearly 8 in 1,000 adults aged 65 years or older experienced one of the four most common ADEs (steroids, antibiotics, opiates/narcotics, and anticoagulants) during hospitalization. A study showed that 48% of patients had an adverse drug reaction to at least one drug, and pharmacist involvement helps to pick up adverse drug reactions. In 2012, McKinsey & Company concluded that the cost of the 50-100 million preventable error-related adverse drug events would be between US$18–115 billion. See also Alleged problems in the drug approval process Classification of Pharmaco-Therapeutic Referrals Drug therapy problems EudraVigilance (European Union) History of pharmacy Iatrogenesis Lethal dose List of withdrawn drugs Paradoxical reaction Polypharmacy Toxicity Toxicology The Medical Letter on Drugs and Therapeutics Yellow Card Scheme (UK) References Further reading Incidence of adverse drug reactions in human immune deficiency virus-positive patients using highly active antiretroviral therapy External links Pharmacy Clinical pharmacology Drug safety