Patients with chronic obstructive pulmonary disease are at a significantly increased risk for hospitalization for community-acquired pneumonia (CAP), compared with patients without COPD, a large prospective study has found.
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Jose Bordon, MD, and colleagues aimed to define incidence and outcomes of COPD patients hospitalized with pneumonia in the city of Louisville, Ky., and to extrapolate the burden of disease in the U.S. population. They conducted a secondary analysis of data from the University of Louisville Pneumonia Study, a prospective population-based cohort study of all hospitalized adults with CAP who were residents in the city of Louisville, Ky., from June 1, 2014, to May 31, 2016.
COPD prevalence in the city of Louisville was derived via data from the 2014 Behavioral Risk Factor Surveillance System (BRFSS) as well as from the 2014 National Health Interview Survey (NHIS). In addition, the researchers analyzed clinical outcomes including time to clinical stability (TCS), length of hospital stay (LOS), and mortality, according to Dr. Bordon, an infectious disease specialist at Providence Health Center, Washington, and colleagues on behalf of the University of Louisville Pneumonia Study Group.
The researchers found an 18-fold greater incidence of community-acquired pneumonia in patients with COPD, compared with non-COPD patients.
A total of 18,246 individuals aged 40 and older with COPD were estimated to live in Louisville, Ky. The researchers found that 3,419 COPD patients were hospitalized due to CAP in Louisville during the 2-year study period. COPD patients, compared with non-COPD patients, were more likely to have a history of heart failure, more ICU admissions, and use of mechanical ventilation, compared with patients without COPD. The two groups had similar pneumonia severity index scores, and 17% received oral steroids prior to admission. COPD patients had more pneumococcal pneumonia, despite receiving pneumococcal vaccine significantly more often than non-COPD patients.
The annual incidence of hospitalized CAP was 9,369 cases per 100,000 COPD patients in the city of Louisville. In the same period, the incidence of CAP in patients without COPD was 509 per 100,000, a more than 18-fold difference.
Although the incidence of CAP in COPD patients was much higher than in those without, the difference didn’t appear to have an impact on clinical outcomes. There were no clinical differences among patients with vs. without COPD in regard to time to reach clinical improvement and time of hospital discharge, and in-hospital mortality was not statistically significantly different between the groups, the authors reported. The mortality of COPD patients during hospitalization, at 30 days, at 6 months, and at 1 year was 5.6% of patients, 11.9%, 24.3%, and 33.0%, respectively vs. 6.6%, 14.2%, 24.2%, and 30.1% in non-COPD patients. However, 1-year all-cause mortality was a significant 25% greater among COPD patients, as might be expected by the progression and effects of the underlying disease.
“[Our] observations mean that nearly 1 in 10 persons with COPD will be hospitalized annually due to CAP. This translates into approximately 500,000 COPD patients hospitalized with CAP every year in the U.S., resulting in a substantial burden of approximately 5 billion U.S. dollars in hospitalization costs,” the researchers stated.
“Modifiable factors associated with CAP such as tobacco smoking and immunizations should be health interventions to prevent the burden of CAP in COPD patients,” even though “pneumococcal vaccination was used more often in the COPD population than in other CAP patients, but pneumococcal pneumonia still occurred at a numerically higher rate,” they noted.
The study was supported by the University of Louisville, Ky., with partial support from Pfizer. The authors reported having no conflicts.
SOURCE: Bordon JM et al. Clin Microbiol Infect. 2019 Jun 26; doi: 10.1016/j.cmi.2019.06.025.