The increase in midlife mortality after 1999 was greatly influenced by the increase in fatal drug overdoses. Heroin use increased substantially in the 1960s and 1970s, as did crack cocaine abuse in the 1980s, disproportionately affecting (and criminalizing) the black population.74,75 Mortality from drug overdoses increased exponentially from the 1970s onward.76 The sharp increase in overdose deaths that began in the 1990s primarily affected white populations and came in 3 waves: (1) the introduction of OxyContin in 1996 and overuse of prescription opioids, followed by (2) increased heroin use, often by patients who had become addicted to prescription opioids,77 and (3) the subsequent emergence of potent synthetic opioids (eg, fentanyl analogues)—the latter triggering a large post-2013 increase in overdose deaths.29,78,79 That white populations first experienced a larger increase in overdose deaths than nonwhite populations may reflect their greater access to health care (and thus prescription drugs).5,80 That non-Hispanic black and Hispanic populations experienced the largest relative increases in fentanyl deaths after 201181 may explain the retrogression in overdose deaths observed in these groups.49 Geographic differences in the promotion and distribution of opioids may also explain the concentration of midlife deaths in certain states.82
However, the increase in opioid-related deaths is only part of a more complicated phenomenon and does not fully explain the increase in midlife mortality rates from other causes, such as alcoholic liver disease or suicides (85.2% of which involve firearms or other nonpoisoning methods83). Opioid-related deaths also cannot fully explain the US health disadvantage, which began earlier (in the 1980s) and involved multiple diseases and nondrug injuries.5–7 Two recent studies estimated that drug overdoses accounted for 15% or less of the gap in life expectancy between the United States and other high-income countries in 2013 and 2014, respectively.84,85
“The National Research Council examined the US health disadvantage in detail and identified 9 domains in which the United States had poorer health outcomes than other high-income countries: these included not only drug-related deaths but also adverse birth outcomes, injuries and homicides, adolescent pregnancy and sexually transmitted infections, HIV and AIDS, obesity and diabetes, heart disease, chronic lung disease, and disability.7 Compared with the average mortality rates of 16 other high-income countries, the United States has lower mortality from cancer and cerebrovascular diseases but higher mortality rates from most other major causes of death, including circulatory disorders (eg, ischemic heart and hypertensive diseases), external causes (eg, drug overdoses, suicide, homicide), diabetes, infectious diseases, pregnancy and childbirth, congenital malformations, mental and behavioral disorders, and diseases of the respiratory, nervous, genitourinary, and musculoskeletal systems. According to one estimate, if the slow rate of increase in US life expectancy persists, it will take the United States more than a century to reach the average life expectancy that other high-income countries had achieved by 2016.10
Tobacco Use and Obesity
Exposure to behavioral risk factors could explain some of these trends. Although tobacco use in the United States has decreased, higher smoking rates in prior decades could have produced delayed effects on current tobacco-related mortality and life expectancy patterns, especially among older adults.6,87,88 For example, a statistical model that accounted for the lag between risk factor exposure and subsequent death estimated that much of the gap in life expectancy at age 50 years that existed in 2003 between the United States and other high-income countries—41% of the gap in men and 78% of the gap in women—was attributable to smoking.89 Smoking explained 50% or more of the geographic differences in mortality within the United States in 2004.88,90 However, it is unclear whether smoking, which has declined in prevalence, continues to have as large a role in current life expectancy patterns or in explaining increases in mortality among younger adults.
The obesity epidemic, a known contributor to the US health disadvantage,6 could potentially explain an increase in midlife mortality rates for diseases linked to obesity, such as hypertensive heart disease91 and renal failure.92 As long ago as 2005, the increasing prevalence of obesity prompted Olshansky et al93 to predict a forthcoming decrease in US life expectancy. By 2011, Preston et al94 estimated that increases in obesity had reduced life expectancy at age 40 years by 0.9 years. Elo et al33 noted that changes in obesity prevalence had the largest correlation with geographic variations in life expectancy of any variable they examined.
However, neither smoking nor obesity can fully explain current mortality patterns, such as those among younger adults and increasing mortality from conditions without known causal links to these risk factors. Suggesting that other factors may be at play, Muennig and Glied noted that Australia and other countries with patterns of smoking and obesity similar to those in the United States achieved greater gains in survival between 1975 and 2005.13
Deficiencies in Health Care
Deficiencies in the health care system could potentially explain increased mortality from some conditions. Although the US health care system excels on certain measures, countries with higher life expectancy outperform the United States in providing universal access to health care, removing costs as a barrier to care, care coordination, and amenable mortality.95–97 In a difficult economy that imposes greater costs on patients,98 adults in midlife may have greater financial barriers to care than children and older adults, who benefit from the Children’s Health Insurance Program and Medicare coverage, respectively.99 Although poor access or deficiencies in quality could introduce mortality risks among patients with existing behavioral health needs or chronic diseases, these factors would not account for the underlying precipitants (eg, suicidality, obesity), which originate outside the clinic. Physicians contributed to the overprescription of opioids,100 and iatrogenic factors could potentially explain increases in midlife mortality from other causes, but empirical evidence is limited. Nor would systemic deficiencies in the health care system explain why midlife death rates increased for some chronic diseases while decreasing greatly for others (eg, ischemic heart disease, cancer, and HIV infection)…”
Woolf SH, Schoomaker H. Life Expectancy and Mortality Rates in the United States, 1959-2017. JAMA. 2019;322(20):1996–2016. doi:https://doi.org/10.1001/jama.2019.16932