This study reports several important findings regarding pneumonia-related mortality in the US from 1999 to 2020. While seeing overall mortality rates decrease, males experienced a larger AAMR decrease than females, African American and Black people experienced the highest mortality throughout the duration of the study, and American Indian and Native Alaskan people had the greatest reduction in mortality. Nursing home deaths decreased over time, and in turn, hospice deaths substantially rose. Deaths among people 85 and older steadily declined. Lastly, several geographical differences in AAMR were found between urban-rural groups, states, and census regions.
A decrease in pneumonia-related mortality rates reflects improvements made in pneumonia care. Over the past 22 years, we have seen the sophistication of the pneumonia and influenza vaccines and an increase in vaccine utilization. The CDC has issued guidelines for annual influenza and pneumococcal vaccines for vulnerable populations[11]. Between 2005 and 2014, the CDC reported that the number of individuals receiving the influenza vaccine doubled (43.7%)[6,12]. Greater vaccine adherence may be reflected in lower mortality rates, as one study in Brazil found that overall mortality fell by 23.6% among individuals 65 and older who were vaccinated[13]. While vaccines play a vital role in reducing influenza incidence and preventing subsequent pneumonia, other key medical advances include rapid viral testing for early detection and prompt treatment[14].
While both sexes saw a decrease in mortality, AAMR for males decreased more than that of females. Males experience greater midlife mortality than females, with pneumonia being a factor that offsets the decline in life expectancy for both genders[15]. Females have also reported higher vaccination rates than males[12]. Further research on differences in gender and pneumonia-related mortality is needed, as looking at mortality without separating males and females can mask specific trends[15].
African Americans and Blacks had the highest overall mortality during the study. In addition to pneumonia-related mortality, this population experiences higher overall mortality[16]. There are many complex factors contributing to poorer health outcomes in African American and Black patients, which include social determinants of health such as socioeconomic status, insurance, and access to primary care[16,17]. These barriers to care may contribute to differences in vaccine rates as well. Studies have found that vaccine rates are lower amongst the Black population compared to other racial/ethnic groups[2,11]. Social determinants of health create issues surrounding vaccine accessibility, but increasing campaigns and education surrounding vaccinations in the African American and Black population may be an area of improvement[18].
American Indian and Native Alaskan people had the greatest reduction in mortality from pneumonia[19]. Prior studies have highlighted this group as a higher risk for pneumonia complications. One hypothesis for this trend is increased vaccination adherence. The Office of Minority Health, a branch of the US Department of Health and Human Services, reported a vaccination ratio of 0.8 for American Indian and Alaskan people compared to non-Hispanic and White Americans for the 2019–2020 influenza season[20].
As mortality changes among different populations, we have also seen shifts in where pneumonia deaths occur, with utilization of hospice services on the rise. A report from Medicare beneficiaries found that hospice services increased by 28.8% between 2000 and 2015[21]. Nursing homes also contract with hospice facilities to move patients when their health needs change, leading to a greater number of patients dying in hospice care rather than nursing facilities[22].
Advanced age leads to an increased risk for comorbid illnesses as well. Thus, the 85 and older age group has the greatest risk for complications regarding pneumonia. As medical improvements are made to treat these comorbidities, patients in this age category may have better outcomes regarding pneumonia-related illnesses. Additionally, vaccine efforts to target high-risk groups and patients over 65 years of age have helped reduce the spread of influenza and pneumonia[23,24]. Vaccine rates are highest among the 65 and older population[6,12]. In 2014, 58.7 percent of elderly adults reported receiving at least one kind of pneumococcal vaccine[6,12]. With greater improvements in decreasing mortality and higher vaccination rates, this outcome may support a larger effort to increase vaccinations among other age categories.
Another population comprised of older individuals is rural communities[25]. Rural areas had higher mortality rates and worse health outcomes due to increased distance from healthcare institutions, higher rates of poverty, and greater comorbidities due to lack of consistent care[25,26]. Another explanation for the improvement in mortality among population-dense areas is a greater concentration of college-educated people[27]. Vaccine campaigns have been shown to be successful in cities, especially when targeting high-risk populations[18,28,29].
On a statewide level, there were several trends. States with the highest rates of pneumonia-related mortality were predominantly located in the South, except for New York, which was also among the states with the highest death rate from pneumonia. When comparing by regions, the South had the greatest decrease in AAMR. Studies have found that overall mortality, especially in the rural South, is greater than in other geographical regions for proposed reasons of improved overall health outcomes and increased population density, leading to fewer rural southern communities[25,26]. Colorado was the state that saw the greatest change in AAMR. Compared to Arkansas, which had a similar AAMR in 1999, Colorado decreased its AAMR by over 27.8 and Arkansas by 11.4. This significant decrease in mortality compared to other states is an interesting finding, and understanding the factors that played a role in this improvement could be applied across the USA. A 2019 study by Woolf focused on life expectancy rather than pneumonia-related mortality and found that Colorado's life expectancy difference increased between Colorado and Kansas from 1990 to 2016[27]. This study hypothesized that outcome changes may reflect policy choices considering differences in demography and economies between the two states were low[27]. A 2004–2006 report from the CDC found Colorado to have the highest influenza vaccination and pneumococcal rates amongst their 65 and older population, at 76.5% and 71.4%, respectively, contributing positively to their lower AAMR[30]. While California’s vaccination rates from the same study were middle to lower in ranking, they saw the smallest decrease in AAMR over the study duration (20). Considering vaccination rates, factors resulting in consistent mortality outcomes may be related to lower overall mortality rates. Life expectancy in California ranks among the top five states[31]. This could be related to policies and projects such as the Healthy Cities and Communities Program, the oldest WHO campaign in the US to promote healthier lifestyles, focusing on social determinants of health[32,33].
This study has several limitations to be mindful of. First, the CDC WONDER database is based on death certificates for US residents. Any errors in these certificates could affect data points in the study. Mortality data is coded by death certificates in the state where the deaths took place and may inaccurately represent deaths from patients who traveled for care. We only used the mortality data for pneumonia as the underlying cause of death, which does not consider the deaths where pneumonia might have contributed indirectly to mortality or acted as a secondary cause.