SESSION TYPE: Pneumonia Morbidity and Mortality
PRESENTED ON: Sunday, October 21, 2012 at 01:15 PM - 02:45 PM
PURPOSE: Compared to community-acquired pneumonia (CAP) healthcare-associated pneumonia (HCAP) is characterized by more resistant pathogens and higher mortality rates. The reason for this mortality difference remains unclear. We assessed the extent to which comorbidities and presenting severity of illness explain this mortality increase.
METHODS: Using Premier’s Perspective database, we conducted a retrospective cohort study among adult patients admitted to 347 hospitals with CAP or HCAP 7/1/07-6/30/10. We included all adults with an ICD-9 code for pneumonia as principal diagnosis or as a secondary diagnosis in the setting of respiratory failure or sepsis, together with a radiographic study and antibiotic administration within 48 hours of admission. HCAP was defined if ≥1 of the following criteria was present: 1) Prior hospitalization within 90 days of the index hospitalization, 2) Hemodialysis, 3) Admission from a skilled nursing facility, 4) Immune suppression. We compared the demographic and clinical characteristics of CAP and HCAP groups and explored the independent contribution of HCAP criteria to mortality in a hierarchical generalized linear model (HGLM).
RESULTS: Of 250,907 patients hospitalized with pneumonia, 85,097 (34%) had HCAP. Compared to those with CAP, patients with HCAP were older, more likely to have comorbidities, and to require ICU care, vasopressors and mechanical ventilation. Unadjusted mortality was higher in HCAP than CAP (11.3% vs. 5.1%, p<0.0001). After adjustment for patient demographics, comorbidities, presence of other infections, need for ICU admission, ability to take oral medications, chronic and acute medications, early tests and therapies in a HGLM, the odds ratio (OR) of hospital death remained elevated in HCAP (OR 1.43, 95% confidence interval 1.38-1.48) relative to CAP. The odds of death increased for each additional HCAP criterion (OR 1 criterion = 1.33, OR 2 criteria=1.67, OR ≥3 criteria 1.93).
CONCLUSIONS: In this large cohort study, comorbidities and presenting illness severity explained >1/2 the mortality difference between HCAP and CAP. The remaining difference in mortality may be due to more virulent organisms, inadequate treatment, the HCAP criteria themselves or additional unmeasured confounders.
CLINICAL IMPLICATIONS: HCAP criteria identify a group of patients at risk for higher hospital mortality independent of other markers of illness severity.
DISCLOSURE: The following authors have nothing to disclose: Marya Zilberberg, Peter Lindenauer, Penelope Pekow, Aruna Priya, Richard Brown, Raquel Belforti, Sarah Haessler, Tara Lagu, Daniel Skiest, Michael Rothberg
No Product/Research Disclosure InformationEviMed Research Group, Goshen, MA