摘要Objective This study aimed to evaluate the clinical benefits of a vancomycin dosage strategy based on a serum trough concentration model in elderly patients. Methods This prospective single-center, open-label, randomized controlled trial categorized 66 elderly patients with severe pneumonia into study and control groups. The control group received vancomycin using a regimen decided by the attending physician. Meanwhile, the study group received individualized vancomycin therapy with a dosing strategy based on a serum trough concentration model. The primary endpoint was the proportion of patients with serum trough concentrations reaching the target values. The secondary endpoints were clinical response, vancomycin treatment duration, and vancomycin-associated acute kidney injury (VA-AKI) occurrence. Results All patients were at least 60 years old (median age = 81 years). The proportion of patients with target trough concentration achievement (≥ 15 mg/L) with the initial vancomycin regimen was significantly higher in the study group compared to the control group (75.8％ vs. 42.4％, P = 0.006). Forty-five patients (68.2％) achieved clinical success, the median duration of vancomycin therapy was 10.0 days, and VA-AKI occurred in eight patients (12.1％). However, there were no significant differences in these parameters between the two groups. The model for predicting vancomycin trough concentrations was upgraded to: serum trough concentration (mg/L) = 17.194 ? 0.104 × creatinine clearance rate (mL/min) + 0.313 × vancomycin daily dose [(mg/(kg?d)]. Conclusion A vancomycin dosage strategy based on a serum trough concentration model can improve the proportion of patients achieving target trough concentrations in elderly patients with severe pneumonia.