Acute vascular insufficiency of intestine: incidence highest in summer, outcomes worst in winter

Background: The incidence of acute vascular insufficiency of intestine (AVII) is on the rise in the USA and is associated with significant morbidity and mortality. Seasonal variations have been observed in the onset of several gastrointestinal diseases. It is thus far unknown whether the incidence, in-hospital mortality rates, and length of hospital stay (LOS) of AVII vary in different seasons. Aims: The aims of this study were to study the seasonal variations in the (1) incidence, (2) in-hospital mortality, and (3) LOS of AVII in the USA. Methods: We used the Nationwide Inpatient Sample to identify patients aged ≥ 18 years hospitalized from the years 2000–2014. We used the Edwards recognition with estimation of cyclic trend method to study the seasonal variation of AVII hospitalizations and z test to compare the seasonal incidences (peak-to-low ratio), mortalities, and LOS. Results: A total of 1,441,447 patients were hospitalized with AVII (0.3% of all hospitalizations). Patients with AVII were older (69.0 ± 0.1 vs 56.9 ± 0.1) and more commonly females (65.4% vs 35.5%) than patients without AVII (p < 0.001). The incidence of AVII increased through the summer to peak in September (peak/low ratio 1.028, 95% CI 1.024–1.033, p < 0.001). Patients with AVII hospitalized in winter had the highest mortality (17.3%, p < 0.001) and LOS (9.2 ± 0.7 days, p < 0.001). Conclusions: The incidence of AVII in the USA peaks in late summer. The in-hospital mortality rates and LOS associated with AVII are the highest in winter. Physicians could be cognizant of the seasonal variations in the incidence, in-hospital mortality, and LOS of AVII.