Study population and patient settings
This study was approved by the Institutional Review Board of Nagano
Prefectural Shinshu Medical Center (approval no: ShinshurinriR3-2,
Suzaka City, Japan). As this was a retrospective analysis, informed
consent was not required to participate in the study. This retrospective
study was conducted at a single facility (an acute-phase community
hospital with 300 beds). We extracted the medical records of patients
aged ≥ 65 years who were hospitalized at our institution between April
2014 and March 2016 and who were diagnosed with aspiration pneumonia as
their primary disease. We selected patients who met the criteria of CAP
according to the clinical guidelines of the American Thoracic Society
and Infectious Disease Society of America. Patients with
hospital-acquired pneumonia (HAP) (Figure 1) were
excluded.3 The diagnosis of aspiration pneumonia was
defined based on clinical symptoms indicative of pneumonia (i.e., cough,
sputum, and fever), infiltration on chest imaging (chest X-ray or
computed tomography), and findings of aspiration assessed by a trained
speech therapist (ST) and/or nurse in rehabilitation programs.