Fig. 4.

Results of simultaneous noninferiority hypothesis tests among randomized femoral nerve catheter insertion treatments (SC = stimulating catheter, SN = stimulating needle, and US = ultrasound alone), given as estimates and 95% confidence intervals (confidence intervals adjusted for simultaneous inference and interim monitoring). One treatment (say, SN) was declared noninferior to another treatment (say, US) on mean VRS pain score when the estimated difference in means was significantly less than the pre-specified noninferiority delta of 0.5 points (given as the dashed vertical line). Likewise, SN was declared noninferior to US on mean total IV morphine equivalent dose if the mean for SN was significantly not more than 25% greater than the mean for US. Significant noninferiority (as assessed by the Holm-Bonferroni step-down method) is given by asterisks next to the raw P-values. VRS = verbal response scale