What Was the Leading Cause of Death in 2015?

The Centers for Disease Control and Prevention’s National Center for Health Statistics (NCHS) recently released a report on mortality in the United States, providing the public with insight into life expectancy, age-adjusted death rates pertaining to race/ethnicity and sex, and the leading causes of death for adults and infants. A number of infectious diseases remained on the list among the top 10 leading causes.

According to the NCHS, in 2015, the estimated life expectancy—what they define as “the expected average number of years of life remaining at a given age”—at time of birth for the overall United States population was 78.8 years; a drop from 78.9 years in 2014. This is the first reported decrease in life expectancy in more than two decades. In 1993, life expectancy dropped from 75.8 years in 1992 to 75.5 years in 1993. This decrease in life expectancy was noted in both sexes; however, the analysis showed a decrease of 0.2 years (from 76.5 in 2014 to 76.3 last year) in men, whereas for females, it showed a decrease of 0.1 years (from 81.3 in 2014 to 81.2 last year). The NCHS reported that overall, females had a higher life expectancy than their male counterparts and the report indicates that the difference in life expectancy between the sexes actually increased by 0.1 years (4.8 years to 4.9 years’ difference) from 2014 to 2015.

Despite this recent decrease, life expectancy is still higher than what had been estimated a decade ago (77.4 years).

The NCHS also includes “age-adjusted death rates,” which the authors noted as being incredibly useful “when comparing different populations because they remove the potential bias that can occur when the populations being compared have different age structures.” In their comparative analysis, they found that overall, the age-adjusted death rate for the total US population increased by 1.2% from 2014 (724.6 per 100,000 standard population) to 2015 (733.1 per 100,000 standard population).

The authors found that the race/ethnicity/sex groups that experienced increases in these death rates consisted of non-Hispanic black males (0.9%), non-Hispanic white males (1.0%), and non-Hispanic white females (1.6%). In addition, the authors reported that rates pertaining to non-Hispanic black females, Hispanic females, and Hispanic males did not show significant changes from 2014 to 2015.

According to the report, heart disease still tops the list of leading causes of death in the United States, as it has for the past decade, with “cancer, chronic lower respiratory diseases, unintentional injuries, strokes, Alzheimer’s disease, diabetes, influenza and pneumonia, kidney disease, and suicide” also making the top 10 list for 2015; all ten of these causes of death made the list in 2014, as well. In 2015, these causes were accountable for a whopping 74.2% of total US deaths. Chronic lower respiratory diseases, influenza, and pneumonia have made the top 10 list of leading causes of death for at least a decade, with chronic lower respiratory diseases taking either the third or fourth spot on the list and influenza and pneumonia remaining in the eighth spot, with the exception of 2010, where it ranked ninth on the list.

The authors also reported that for eight of the 10 aforementioned causes of death, the age-adjusted death rates showed an increase and only one of the top 10 causes of death, cancer, experienced a decrease (1.7%) in these death rates. The authors wrote, “The rate increased 0.9% for heart disease, 2.7% for chronic lower respiratory diseases, 6.7% for unintentional injuries, 3.0% for stroke, 15.7% for Alzheimer’s disease, 1.9% for diabetes, 1.5% for kidney disease, and 2.3% for suicide. Influenza and pneumonia age-adjusted death rates did not experience any significant changes from 2014 to 2015."

A total of 23,455 deaths in 2015 were children under 1 year of age, a number that has increased since 2014, where 23,215 deaths had been reported. According to the authors, the infant mortality rate, or IMR—which they define as “the ratio of infant deaths to live births in a given year”—can serve as an indicator for the health of an entire population. They reported that the change in IMR is not “statistically significant;” however, the rates did rise from 2014 to 2015, going from 582.1 infant deaths per 100,000 live births in 2014, to 589.5 in 2015.

The NCHS reports congenital malformations, low birth weight, sudden infant death syndrome, maternal complications, unintentional injuries, cord and placental complications, bacterial sepsis of newborn, respiratory distress of newborn, diseases of the circulatory system, and neonatal hemorrhage, as the top 10 causes of infant death in 2015. As had been witnessed when looking at the top 10 leading causes of death in adults, the top causes for infants also remained the same from 2014 to 2015. However, the authors noted that two of the causes changed in rank with unintentional injuries experiencing a 11.3% increase since 2014, going from 29.1 infant deaths per 100,000 live births to 32.4. Other than this, the authors report that the other causes did not show significant changes from 2014 to 2015.