The natural history of an epidemic

According to the World Bank Group, the country's average life expectancy fell from 78.8 years in 2014 to 78.7 years in 2015, and then to 78.5 years in 2016 and 2017. The structure of the health-care system in the United States also contributed to the overprescription of opioids. Because many doctors are in private practice, they can benefit financially by increasing the volume of patients that they see, as well as by ensuring patient satisfaction, which can incentivize the overprescription of pain medication. According to a study led by Cerdá, people with a history of using prescription opioids are 13 times more likely to start using heroin than those with no history of prescription opioid misuse4. According to the US Centers for Disease Control and Prevention, between 2013 and 2016, overdose deaths from fentanyl and similar molecules increased by 88% per year.