Table 1: Select risk factors for MRSA and Pseudomonas in community-onset pneumonia.

Organism Risk Factor Evidence Summary
MRSA Hemodialysis Observational cohort (prospective): Identification of dialysis during the preceding 30 days as a risk factor for MRSA among CAP/HCAP patients [11]
Prior influenza Observational cohort and case-series (retrospective): Influenza association with subsequent MRSA pneumonia [12-14]
Illicit drug use Observational cohort and a case-control study (retrospective): identification of illicit drug use as a risk factor associated with MRSA [15,16]
COPD Observational cohort and case-control study (retrospective): COPD identified as a risk factor for MRSA pneumonia [15,17]
Prior antibiotic therapy Observational cohorts and a case-control study (prospective and retrospective): antibiotic exposure within 90 days of pneumonia occurrence associated with MRSA pneumonia [11,15,17]
Prior hospitalization Observational cohort (prospective): identification of hospitalization for two days or more during the preceding 90 days as a risk factor for MRSA among CAP/HCAP patients [11,15]
Pseudomonas COPD/structural lung disease Observational cohorts (prospective and retrospective): COPD and structural lung disease associated with Pseudomonas pneumonia [17,18]
Prior antibiotic therapy Observational cohort (retrospective): antibiotic exposure within 90 days of pneumonia occurrence associated with Pseudomonas pneumonia [17]
Prior hospitalization Observational cohort (prospective): identification of hospitalization for two days or more during the preceding 90 days as a risk factor for Pseudomonas pneumonia [17,18]

*MRSA infection not limited to pneumonia.