Same-day emergency care: a retrospective observational study of the incidence and predictors of venous thromboembolism following hospital-based acute ambulatory medical care.

Background: Same-day emergency care (SDEC) is an expanding area of hospital acute medical care. It aims to minimize delays and manage medical emergency patients within the same day, enabling hospitalization to be avoided; the expectation is that the patients would have required inpatient hospitalization in the absence of the SDEC service. Venous thromboembolism (VTE) prevention is a key medical inpatient safety measure. Whether VTE prevention should be considered for SDEC patients is unknown.

Objectives: To examine the incidence and predictors of VTE diagnosed within 90 days of SDEC assessment.

Methods: Data were obtained from electronic health records of people who received SDEC at our hospital during a 5-year period (April 2016 to March 2021).

Results: There were 40 045 attendance episodes by 33 715 individuals. Median age was 60 years (IQR, 41.0-76.0 years), and 55.2% were women. Three hundred forty-nine patients (0.9%) developed a VTE within 90 days of SDEC. Increased risk of VTE was associated with age more than 60 years, prior malignancy (adjusted odds ratio [OR], 4.12; 95% CI, 3.19-5.32; P < .0001), history of diseases of the circulatory system (adjusted OR, 2.92; 95% CI, 2.27-3.76; P < .0001), and having 1 or more additional SDEC attendances within 30 days (adjusted OR, 4.61; 95% CI, 3.65-5.82; P < .0001). In the 90 days prior to VTE diagnosis, 36.6% of patients had a separate inpatient admission in addition to SDEC. There was no association with completion of an electronic VTE risk assessment (adjusted OR, 0.96; 95% CI, 0.76-1.20).

Conclusion: The incidence of VTE following SDEC is similar to that reported for symptomatic VTE in traditional medical inpatients without thromboprophylaxis.