Association Between Early Point-of-Care Ultrasound and Emergency Department Outcomes in Admitted Patients with Non-Traumatic Abdominal Pain: A Propensity Score-Weighted Cohort Analysis

<b>Background</b>: To evaluate the association of point-of-care ultrasound (PoCUS) performed within one hour of emergency department (ED) arrival with ED length of stay (LOS) and healthcare costs in admitted ED patients with non-traumatic abdominal pain. <b>Methods:</b> This retrospective, inverse probability of treatment weighting (IPTW) cohort study was conducted at a tertiary medical center in Taiwan. This study analyzed data from 2021-2023, focusing on adult patients admitted to an ordinary ward with non-traumatic abdominal pain. Patients discharged from the ED, admitted to the ICU, or receiving PoCUS > 1 h (N = 864) were excluded. The final cohort of 6866 patients comprised those receiving PoCUS within 1 h (N = 1542) and those receiving no PoCUS (N = 5324). Primary and secondary outcomes (ED LOS, costs) were adjusted for age, gender, triage, vital signs, BMI, and comorbidities using generalized linear models with a Gamma distribution. <b>Results:</b> After IPTW adjustment in 6866 admitted abdominal pain patients, PoCUS within one hour was associated with a 14% shorter ED LOS (RM 0.86, 95% CI 0.83-0.89). A notable finding was that PoCUS performed within one hour was associated with 44% higher odds of CT utilization (OR 1.44, 95% CI 1.25-1.65) and 5% lower total healthcare costs (RM 0.95, 95% CI 0.91-0.99). Stratification by CT use revealed distinct patterns underlying these associations: in the non-CT subgroup, PoCUS was associated with 12% lower ED costs (RM 0.88, 95% CI 0.83-0.94), whereas in the CT subgroup, it was associated with 9% lower admission costs (RM 0.91, 95% CI 0.86-0.96). <b>Conclusions:</b> In admitted patients, PoCUS performed within one hour was associated with shorter ED LOS and lower total costs, despite a concurrent association with higher CT utilization. These findings are consistent with a dual, context-dependent role for PoCUS: associated with reduced ED costs in non-CT pathways and lower admission costs in CT pathways. However, as this is an observational study, these results represent associations rather than causal effects and may be influenced by unmeasured confounding. Prospective trials are required to validate these findings.