Epidemiology and Recurrence of Sigmoid Volvulus: Analysis of Health Insurance Claims Data in Japan.

Objectives: Sigmoid volvulus (SV) is rare in Japan, and most studies have been limited to small numbers or case series reports. We aimed to explore the incidence, risk factors, and recurrence rates of SV in Japan using community-based health insurance claims data. Methods: We used health insurance claims data from the Toyama Prefecture from April 2018 to March 2022. Individuals aged ≥ 40 years who had no diagnosis of SV (International Statistical Classification of Diseases, 10th Revision) in 2018 were included in our study. Patients who were newly diagnosed with SV in 2019 were identified. The annual incidence, risk factors, and recurrence rates of SV within 2 years of the first endoscopic reduction were evaluated. Poisson regression analysis was employed to identify risk factors, and Kaplan-Meier analysis was performed to analyze recurrence. Results: Of the 327,693 insured individuals in Toyama, 52 developed SV in 2019 (0.0159% = 15.9/100,000). Men (adjusted rate ratio [aRR] = 3.46, 95% confidence interval [CI]: 1.92- 6.25), constipation (aRR = 4.63, 95% CI: 2.50-8.58), and higher disability levels (level 2-3: aRR = 6.54, 95% CI: 2.43-13.57, level 4-5: RR = 2.94, 95% CI: 1.10-7.84) were significantly associated with SV incidence. Of the 45 patients who underwent only endoscopic reduction, recurrence within 2 years was observed in 16 (cumulative recurrence rate, 35.6%). Conclusions: SV is common in community-based studies. Men, constipation, and a high disability level were risk factors. The recurrence rate of SV after endoscopic reduction was approximately 35% within 2 years. Our insurance claims data offered valuable insights into SV epidemiology.