INTRODUCTION
Aspiration pneumonia is a clinical syndrome that often develops in patients with impaired swallowing function and cough reflex or those with underlying diseases associated with dysphagia such as cerebrovascular diseases, dementia, and Parkinson’s disease.1 Concomitant with aging of the population, the incidence of aspiration pneumonia in older adults is increasing and is associated with higher mortality rates. Indeed, aspiration pneumonia accounts for 70% of pneumonia in patients aged ≥70 years.2 Despite its high morbidity and mortality, clinical features and prognostic factors for aspiration pneumonia in older patients remain poorly defined.
Current clinical guidelines for pneumonia emphasize optimal antibiotic strategies based on estimated causative pathogens.3-5Based on these guidelines, the location of infection and several risk factors are utilized to determine the appropriate treatment strategy and prognostic evaluation. Nevertheless, these algorithms may be unsuitable for patients with aspiration pneumonia owing to the heterogeneity of this patient population.6
Older adults commonly experience nutritional issues associated with declining organ and physical functions, underlying diseases, and inadequate dietary habits.7 In hospitalized settings for older individuals, undernutrition is associated with poor clinical outcomes such as longer hospital stay and higher mortality rate.8,9 Thus, in geriatric clinical practice, the assessment of nutritional status is crucial for improving prognosis and anticipating subsequent clinical course. The geriatric nutritional risk index (GNRI) is a simple and objective index proposed by Bouillanne et al. to evaluate nutritional risk in hospitalized older patients.10 GNRI was recently reported to be a useful tool for predicting mortality in older patients with hemodialysis,11 heart failure,12 various cancers,13-15 and trauma.16 Wei et al. reported that GNRI demonstrated superior predictive value for poor prognosis compared with other inflammatory indicators in older patients with severe community-acquired pneumonia (CAP).17 Nevertheless, the prognostic utility of GNRI in older patients with aspiration pneumonia remains unclear. Therefore, this study aimed to investigate the prognostic utility of GNRI in older patients with aspiration pneumonia.