July effect on outcomes of catheter-directed therapies for pulmonary embolism in teaching hospitals: insights from the National Inpatient Sample, 2016 to 2022.

BACKGROUND

The "July effect" has been hypothesized to worsen outcomes during annual trainee turnover in teaching hospitals. Whether this applies to catheter-directed therapies for pulmonary embolism (PE) is unknown.

METHODS

We analyzed the National Inpatient Sample (2016-2022) to identify adults with a principal PE diagnosis undergoing catheter-directed therapies, including catheter-directed thrombolysis and percutaneous mechanical thrombectomy, at teaching hospitals (unweighted n = 5175). The exposure was a July admission. Outcomes were in-hospital mortality, length of stay, total charges, acute kidney injury, dialysis, and mechanical ventilation. Models adjusted for age, sex, race, comorbidity burden, payer, income quartile, hospital region, and bed size. A sensitivity analysis examined June versus non-June admissions using the same modeling strategy.

RESULTS

July admission was not associated with an increase in in-hospital mortality (odds ratio [OR] 1.11, 95% confidence interval [CI] 0.85-1.43; P = 0.44). Length of stay was similar (β= +0.19 days, 95% CI -0.62 to +0.99; P = 0.65), as were total charges (geometric mean ratio 0.96, 95% CI 0.90-1.02; P = 0.21). July admission was also not associated with acute kidney injury (OR 1.02, 95% CI 0.82-1.27; P = 0.85), dialysis (OR 0.90, 95% CI 0.39-2.04; P = 0.80), or mechanical ventilation (OR 0.85, 95% CI 0.67-1.08; P = 0.19).

CONCLUSION

July admission was not independently associated with worse mortality, resource use, or in-hospital complications after catheter-directed therapies for PE in teaching hospitals.