Statistical analysis
UC
The sample size of the study was determined by power analysis on one of the primary endpoints: what is the effect of a DA on satisfaction with treatment choice? The power calculation was modified to the patient version of the SDM-Q-9. A difference of 8 was considered as clinically relevant and the standard deviation as calculated from the article was set at 26.02 [The analyses were performed on an intention-to-treat basis, on the assumption that information provision in the DA group was different from that of the UC group because of the introduction of the DA regardless of the actual DA usage by patients. Tests were two-sided and Statistical analysis was performed using IBM SPSS Statistics for Windows, version 25.0 (IBM, Armonk, NY, USA).