Risk Factors for Aspiration Pneumonia in Older Adults

BACKGROUNDS Aspiration pneumonia is a dominant form of community-acquired and healthcare-associated pneumonia, and a leading cause of death among ageing populations. However, the risk factors for developing aspiration pneumonia in older adults have not been fully evaluated. The purpose of the present study was to determine the risk factors for aspiration pneumonia among the elderly. METHODOLOGY AND PRINCIPAL FINDINGS We conducted an observational study using data from a nationwide survey of geriatric medical and nursing center in Japan. The study subjects included 9930 patients (median age: 86 years, women: 76%) who were divided into two groups: those who had experienced an episode of aspiration pneumonia in the previous 3 months and those who had not. Data on demographics, clinical status, activities of daily living (ADL), and major illnesses were compared between subjects with and without aspiration pneumonia. Two hundred and fifty-nine subjects (2.6% of the total sample) were in the aspiration pneumonia group. In the univariate analysis, older age was not found to be a risk factor for aspiration pneumonia, but the following were: sputum suctioning (odds ratio [OR] = 17.25, 95% confidence interval [CI]: 13.16-22.62, p < 0.001), daily oxygen therapy (OR = 8.29, 95% CI: 4.39-15.65), feeding support dependency (OR = 8.10, 95% CI: 6.27-10.48, p < 0.001), and urinary catheterization (OR = 4.08, 95% CI: 2.81-5.91, p < 0.001). In the multiple logistic regression analysis, the risk factors associated with aspiration pneumonia after propensity-adjustment (258 subjects each) were sputum suctioning (OR = 3.276, 95% CI: 1.910-5.619), deterioration of swallowing function in the past 3 months (OR = 3.584, 95% CI: 1.948-6.952), dehydration (OR = 8.019, 95% CI: 2.720-23.643), and dementia (OR = 1.618, 95% CI: 1.031-2.539). CONCLUSION The risk factors for aspiration pneumonia were sputum suctioning, deterioration of swallowing function, dehydration, and dementia. These results could help improve clinical management for preventing repetitive aspiration pneumonia.