Burden of Pneumonia-Associated Hospitalizations: United States, 2001-2014

Abstract

Background: The epidemiology of pneumonia has likely evolved in recent years, reflecting an aging population, changes in population immunity, and socioeconomic disparities.

Methods: Using the National (Nationwide) Inpatient Sample, estimated numbers and rates of pneumonia-associated hospitalizations for 2001-2014 were calculated. A pneumonia-associated hospitalization was defined as one in which the discharge record listed a principal diagnosis of pneumonia or a secondary diagnosis of pneumonia if the principal diagnosis was respiratory failure or sepsis.

Results: There were an estimated 20,361,181 (SE, 95,601) pneumonia-associated hospitalizations in the United States during 2001-2014 (average annual age-adjusted pneumonia-associated hospitalization rate of 464.8 per 100,000 population [95% CI, 462.5-467.1]). The average annual age-adjusted pneumonia-associated hospitalization rate decreased over the study period (P < .0001). In-hospital death occurred in 7.4% (SE, 0.03) of pneumonia-associated hospitalizations. Non-Hispanic American Indian/Alaskan Natives and non-Hispanic blacks had the highest average annual age-adjusted rates of pneumonia-associated hospitalization of all race/ethnicities at 439.2 (95% CI, 415.9-462.5) and 438.6 (95% CI, 432.5-444.7) per 100,000 population, respectively. During 2001-2014, the proportion of pneumonia-associated hospitalizations colisting an immunocompromising condition increased from 18.7% (SE, 0.2) in 2001 to 29.9% (SE, 0.2) in 2014. Total charges for pneumonia-associated hospitalizations in 2014 were over $84 billion.

Conclusions: Pneumonia is a major cause of morbidity and mortality in the United States. Differences in rates and outcomes of pneumonia-associated hospitalizations between sociodemographic groups warrant further investigation. The immunocompromised population has emerged as a group experiencing a disproportionate burden of pneumonia-associated hospitalizations.

Keywords: epidemiology; pneumonia; respiratory failure; sepsis.