Patient characteristics
Data of 634 patients with aspiration pneumonia were collected throughout the study period. Ten patients with HAP, 24 patients aged <65 years, and 13 patients with insufficient data for GNRI were excluded, resulting in a total of 587 eligible patients (Figure 1). Patient characteristics are presented in Table 1. The mean age of patients was 86 ± 9.5 years. The study sample comprised 358 (61%) male individuals and 229 (39%) female individuals. More than half of the patients had lived in a nursing home (50.1%) before admission. Among underlying comorbidities, dementia had the highest prevalence (48%). The mean LOS tended to be longer than the antibiotic administration period (29.9 ± 24 vs. 10.8 ± 6.6 days). Among the patients, 97 (16.5%) died during hospitalization. Regarding the information of antibiotic treatment (Table 1), ampicillin/sulbactam (ABPC/SBT) was the most frequently administered initial antibiotic (85%), followed by piperacillin/tazobactam (PIPC/TAZ) (9.2%). Initial antibiotics were switched to other agents in 112 (19.1%) patients. The results of clinical parameters and laboratory tests are also presented in Table 1. The mean BMI and GNRI were 18.2 ± 3.6 kg/m2 and 83.4 ± 12.9, respectively. Among the patients, 88% were considered to have nutrition risk (GNRI <98) and 279 (47.5%) were considered to have severe risk (GNRI <82) based on GNRI definitions. Microbiological findings are presented in Table 2. Sputum tests were conducted for 521 (88.8%) patients. PDR pathogens were isolated from 156 (29.9%) patient samples.