An analysis of US influenza and pneumonia death trends from 1999 to 2020 shows decreasing overall mortality but disparities by sex, race, region, and age.
For the study, a team led by researchers from Allama Iqbal Medical College in Pakistan calculated crude death rates and age-adjusted mortality rates (AAMRs) per 100,000 Americans for flu and pneumonia using the Centers for Disease Control and Prevention (CDC) Wide-Ranging Online Data for Epidemiologic Research (WONDER) database.
"In the 20th century, influenza and pneumonia constituted the largest proportion of infectious disease deaths in the United States (US)," the researchers wrote. "Despite progress in management, US mortality trends for these diseases have not been thoroughly investigated."
The research was published in the American Journal of Infection Control.
Chronic conditions are risk factors
From 1999-2020, 1,257,088 Americans (AAMR, 17.09 per 100,000) died of flu or pneumonia, with a significant trend to a lower AAMR (-2.94). The AAMRs for pneumonia- and flu-related deaths were 23.49 in 1999 and 13.05 in 2020. The AAMR fell significantly from 1999 to 2010 (annual percentage change [APC], -3.87), followed by a relatively slower decline from 2010 to 2020 (APC, -1.89).
People of color are between 1.3 and 23 times more likely than NH [non Hispanic] Whites to have the underlying conditions that are associated with severe influenza infections and thus experience disproportionately high rates of poor health outcomes and mortality.
"Major reductions in the mortality rates have been observed since the advent of the new century," the study authors wrote. "Age-adjusted mortality rate from influenza and pneumonia has decreased 36% between 1999 and 2010. Reasons for this are multifactorial and may be attributed to recent advancements in the health care system, such as increased vaccination rates, and public health interventions."
People who had one underlying medical condition were 39 times more likely to die of flu or pneumonia than those who had none, while those who had at least two were 202 times more likely. Relative to females, males had a higher AAMR (20.13 vs 15.02). American Indians had the highest AAMR, at 20.44, followed by Black Americans (18.85), while Hispanics had the lowest AAMR, at 13.91.
"People of color are between 1.3 and 23 times more likely than NH [non Hispanic] Whites to have the underlying conditions that are associated with severe influenza infections and thus experience disproportionately high rates of poor health outcomes and mortality," the researchers said.
Elderly at significantly higher risk
The Northeast had the highest AAMR (18.02), and all other regions had similar AAMRs (Midwest, 16.97; South, 16.85; West, 16.59). Rural regions consistently had a higher AAMR (19.80) than their urban counterparts (16.51).
"This regional disparity may be due, in part, to differences in healthcare systems and access to medical treatments," the authors observed. "Socioeconomic factors influencing healthcare quality and inconsistent vaccination rates can also have a substantial impact on mortality rates in different regions."
Tailoring interventions towards high-risk groups can enhance the effectiveness of preventive measures, vaccination, and healthcare access.
States with the highest AAMRs, including Mississippi (23.84), Tennessee (23.53), Arkansas (22.63), and Kentucky (21.77), had rates roughly double those of states with the lowest values, such as Florida (10.64), Vermont (11.08), Minnesota (11.72), and Washington (12.26).
The crude death rate in infants younger than 1 year was 5.61 per 100,000, while it was 0.72 per 100,000 among those aged 1 to 4. People aged 85 years or older had a crude death rate of 481.07 per 100,000, falling to 114.96 in those aged 75 to 84. Of all 1,257,088 flu and pneumonia deaths, 46% were among those aged 85 or older.
"Tailoring interventions towards high-risk groups can enhance the effectiveness of preventive measures, vaccination, and healthcare access," the researchers concluded. "Given that a considerable number of high-risk patients rely on private physicians for their healthcare needs, the pivotal role of these healthcare providers is paramount in ensuring the success of public health strategies aimed at reversing the trends of influenza and pneumonia."
