Statistical Analysis of the Factors that Affect Postoperative Length of Hospital Stay after Unruptured Intracranial Aneurysm Treatment in Japan: A 20-year Nationwide Multicenter Study

Treatment strategies for unruptured intracranial aneurysms (UIAs) should be carefully considered with reference to rupture and complication rates. It is also important to minimize the length of hospital stay (LOS) and to ensure a high quality of medical care. In this study, we aim to clarify the factors that affect the LOS of patients treated for UIAs using the Inpatient Clinico-Occupational Database of the Rosai Hospital Group (ICOD-R). This was a nationwide-multicenter study based on ICOD-R data from 2000 to 2019. Patients diagnosed with UIAs who were treated with clipping or coiling were included in the study. Multivariate analysis was performed to identify the factors affecting LOS. LOS was also compared between groups classified by surgical procedure or treatment period. We identified 3294 patients on the database who underwent clipping or coiling of UIAs during the study period. Multivariate analysis revealed hospital admission during the early 2000s and the late 2010s, age, and treating institution to be significantly correlated with LOS (p < 0.05). There was a significant difference between the mean LOS of the clipping group (20.3 days) and the coiling group (9.65 days) (p < 0.001). Compared by treatment period, LOS significantly shortened over time. Our results suggest that the type of treatment, time of treatment, patient age, and the treating institution affect postoperative LOS for UIAs. Although coiling was found to lead to a lower average LOS than clipping, treatment selection should take the characteristics of each patient's aneurysm into consideration.