Early Acute‐Phase Energy Intake Is Independently Associated With Swallowing Decline in Older Patients With Aspiration Pneumonia: A Retrospective Cohort Study

AIM: Although swallowing decline is common after aspiration pneumonia treatment, the impact of early acute-phase energy intake on swallowing outcomes remains poorly understood. We aimed to clarify the association between acute-phase energy intake (Days 3-7) and swallowing decline at discharge in older patients with aspiration pneumonia. METHODS: This single-center retrospective cohort study included patients aged ≥ 65 years with aspiration pneumonia who maintained oral intake before admission (Functional Oral Intake Scale [FOIS] Score 4-7). The exposure was mean energy intake during Days 3-7 (kcal/kg/day). Swallowing decline was defined as ≥ 1-point FOIS reduction at discharge. We compared the incidence of swallowing decline across energy-intake quartiles and fitted a multivariable logistic regression model, with covariates selected using a directed acyclic graph. ROC and restricted cubic spline analyses were performed. RESULTS: Of 200 patients, 109 (54.5%) experienced swallowing decline at discharge. The incidence decreased across energy-intake quartiles, from 68.0% to 36.0% (p for trend < 0.001). In multivariable analysis, lower energy intake was independently associated with swallowing decline (adjusted odds ratio 0.927, 95% confidence interval 0.885-0.971, p = 0.001). ROC analysis identified an optimal cutoff of 15.3 kcal/kg/day (area under the curve 0.648; sensitivity 69.6%; specificity 57.4%). CONCLUSIONS: Insufficient early acute-phase energy intake was independently associated with swallowing decline in older patients with aspiration pneumonia. Because energy and protein intake were strongly correlated, energy intake below 15.3 kcal/kg/day-possibly reflecting overall macronutrient insufficiency-may serve as a practical reference point for identifying at-risk patients, although prospective validation is needed.