Statistical methods for primary and secondary outcomes {20a}
REGRESSION
Group differences in the mRS and SIS-p scores at the 12-month follow-up will be tested using ordinal logistic (proportional odds) regression, adjusted for site with fixed effects [For the two primary outcomes, adjustments of the significance levels of the individual tests will be performed using the Holm–Bonferroni method to ensure that the familywise error rate will not be inflated above 0.05.Secondary outcomes on an ordinal scale will be analysed similarly using ordinal logistic regression. All analyses will primarily be conducted in accordance with the intention-to-treat principle. As complementary analyses, per-protocol analyses will be performed using data from patients with full availability of primary variables and predefined criteria for adherence. Further details about the statistical analyses will be predefined and published in a separate statistical analysis plan. A data management plan has been established, providing details of the handling, organization and storage of study data.A statistical significance level of 