Mortality from Aspiration Pneumonia: Incidence, Trends, and Risk Factors

Aspiration pneumonia is a potentially preventable, aggressive type of pneumonia. Little is understood on the burden in mortality from aspiration pneumonia. Our objectives were to first examine the burden of mortality from aspiration pneumonia in the United States and second investigate comorbidities associated with aspiration pneumonia to understand risk factors. We conducted a case-control study of individuals who died of aspiration pneumonia matched to those who died of other causes. We analyzed all deaths in the United States using the Multiple Cause of Death Dataset from 1999 to 2017. Cases were matched with controls based on age, sex, and race. We calculated age-adjusted mortality rates, annual percentage changes in aspiration pneumonia mortality, and matched odds ratio comparisons. We identified a total of 1,112,944 deaths related to aspiration pneumonia from 1999 to 2017 or an average of 58,576 per year (age-adjusted mortality rate, 21.85 per 100,000 population; 95% confidence interval (CI) 21.78-21.92). Aspiration pneumonia was reported as the underlying cause of death in 334,712 deaths or an average of 17,616 deaths per year (30.1% of the total aspiration pneumonia-associated deaths). Individuals 75 years old or older accounted for 76.0% of aspiration pneumonia deaths and the age adjusted rate ratio was 161.0 (CI 160.5-161.5). Neurologic, upper gastrointestinal, and pulmonary conditions as well as conditions associated with sedative substances were more often associated with aspiration pneumonia-associated deaths. Aspiration pneumonia is the underlying cause or a cofactor in tens of thousands of deaths each year in the United States. Aspiration pneumonia-associated deaths are highly prevalent with advanced age and are associated with neurologic, upper gastrointestinal and pulmonary conditions.