Statistical analysis
REGRESSION
The trial was analyzed according to the intention-to-treat principle. For this study, patients without guessed treatment allocation (i.e. missing data) by the outcome assessor and patients who died prior to 90-day assessment were excluded. Clinical characteristics of patients included in this study were compared with patients who were excluded because of missing indication of treatment allocation. We described the degree (i.e. number of patients and percentage) of correctly guessed treatment allocations in the total population and stratified by treatment allocation. Whether the percentage of correct guesses was higher than chance (i.e. 50%) was assessed with a binomial probability test (one-sided p value). The difference in the degree of correctly guessed treatment allocations over treatment groups was compared with a chi-square test. We also describe the degree of correctly guessed treatment allocations according to how sure the assessors were of their guess. Differences in the frequencies of how sure the assessors were of their guess between the intervention group versus control group were compared with a Fisher’s exact test. Items that the assessors based their guess upon were described by guessed treatment allocation by the assessor.The association between correctly guessed treatment allocation and the mRS at 90 days was analyzed with ordinal logistic regression stratified by actual treatment allocation and is presented as common odds ratio (cOR) with 95% confidence interval (CI) to indicate statistical precision. We used a multiplicative interaction term to test for interaction of correctly versus incorrectly guessed treatment allocation with actual treatment allocation on the mRS. Statistical analyses were performed with Stata/SE 16.1 (StataCorp, Texas, USA).