Statistical Analyses for Embolization Treatment Outcomes

Data were maintained in an Excel spreadsheet (Microsoft Inc., Redmond, WA, USA) and the statistical analyses were performed on an intention-to-treat basis, using SPSS software (SPSS, version 22 for Windows; SPSS Inc., Chicago, IL, USA) and R/R Studio software. The analyses were based on the modified intention-to-treat population, defined as all randomized patients who received at least one embolization treatment [61 (link),62 (link)]. The Kolmogorov–Smirnov test and the Shapiro–Wilk test were used to verify the normality assumption of data. Categorical data are presented as frequencies (percentage value). Continuous normally distributed data are presented as means ± standard deviations. Continuous not normally distributed data are presented as medians (first–third quartile) [63 (link),64 (link),65 (link)]. The unpaired Student’ t-test was used to assess statistical differences for continuous normally distributed data [66 (link)], whereas categorical and continuous not normally distributed data were assessed using the Chi-squared/Fisher’s exact tests and the Mann–Whitney test, respectively [67 (link),68 (link)]. A p-value of <0.05 was considered statistically significant for the aforementioned tests.