Introduction: The “July effect” refers to the perceived notion that new hospital staff (students, residents, fellows, etc.) first starting training in July may contribute to an increased rate of adverse events during patient care. The purpose of this study is to investigate the effect of July admission on short-term outcome after endovascular coiling of patients with subarachnoid hemorrhage (SAH) due to ruptured aneurysms.
Methods: Data from the National Inpatient Sample (2012 - 2014) was gathered. Adult patients with primary discharge diagnosis of SAH who underwent endovascular therapy at a teaching hospital were identified. Patients with intracranial injury, arteriovenous malformation, and associated craniotomy were excluded. Admissions during July were compared to other months, as well as based on admission quarter: AQ1 (Jul - Sep), AQ2 (Oct - Dec), AQ3, (Jan - Mar), and AQ4 (Apr - Jun). Outcome measures included inpatient morbidity (death, iatrogenic stroke, or myocardial infarction), inpatient mortality, and non-routine discharges.
Results: There were 8,515 patients with diagnosis of SAH who underwent endovascular coiling between 2012 and 2014 from the NIS database. Among these, 665 (7.8%) were admitted in July and 7,850 (92.2%) in other months. Overall, there were no differences in any of the examined outcomes, including morbidity (15.0% vs. 17.3%, p=0.513), mortality (10.5% vs. 11.8%, p=0.665), or non-routine discharge (57.1% vs. 59.7%, p=0.567) for patients admitted in July versus other months, respectively. Based on AQ, 24.5% of patients were admitted in AQ1, 26.0% in AQ2, 23.8% in AQ3, and 25.7% in AQ4. Similar to July vs. other month admissions, there were no significant differences in outcomes based on AQ.
Conclusion: Based on the findings of this national investigation, patients with SAH due to ruptured aneurysms who undergo endovascular therapy during the beginning of the academic year in July may not have worse short-term outcome compared to admissions during other months.