F-36 | July Effect in Outcomes of Patients Admitted with Pulmonary Embolism: A 5-Year United States Study

: There are limited data on the outcomes of patients with pulmonary embolism (PE) admitted to teaching hospitals in the month of July, i.e., when new trainees start their clinical years. All adult (>18 years) non-elective admissions with a primary diagnosis of PE admitted to urban teaching hospitals in month of May and July were identified using the National Inpatient Sample during 2016 to 2020. Outcomes of interest included in-hospital mortality, hospital length of stay, hospitalization costs, and discharge disposition. Results: During 01/01/2016 to 12/31/2020, 103,005 PE admissions were identified in May and July, of which, 52,738 (51.2%) were admitted in July. Both cohorts had comparable age, sex, and racial, and comorbidity distribution. Compared to May, admissions in July, were more frequently during weekends (22.0% vs. 24.3%, p<0.001), had lower rates of non-invasive mechanical ventilation (14.3%vs 14.8%, p=0.29), but comparable acute non-cardiac organ dysfunction (renal [14.3% vs. 14.8%; p=0.29], hepatic [1.0% vs 1.0%; p=0.79]), bleeding complications (5.9% vs 6.2%; p=0.51), and vasopressor use (1.0% vs 0.9%; p=0.33). The two cohorts had similar use of catheter-directed therapies, mechanical or surgical thrombectomy, but the July cohort had higher rates of systemic thrombolysis use (4.0% vs. 3.0%; p<0.001). There were no differences in in-hospital mortality (3.2% vs. 3.1%), length of stay (4.4±0.5 vs 4.4 ±0.4 days), total hospitalization costs ($53,371±820 vs. $52,429±1020), and discharge disposition in admissions during July compared to those from May (all p>0.05). In this five-year study duration, there does not appear to be a ʻJuly Effect' in the care of PE admissions at urban teaching hospitals.