Statistical analysis
AWDs, AWD
REGRESSION, SECONDARY
The sample size was estimated assuming the mean AWD in the control group would be 200 m at 3 monthsThe AWDs of participants who walked more than 15 minutes on the treadmill at 3 months were censored at 790 m. We hypothesized that there would be an improvement in AWD at 3 months in the treatment group compared to the control group in patients with IC by using a prespecified Tobit regression model to incorporate the right-censored data. The model included the AWD baseline measurement, a treatment indicator and the type of centre (SET A predefined statistical analysis plan (SAP) was written. Any analysis not in the SAP is defined as post hoc.The secondary outcome of ICD was analysed using a multilevel Tobit regression at 3, 6 and 12 months to incorporate the right-censored distribution of data. For ABPI, mixed models were used. As the ABPI data showed a skewed distribution, log transformation was used for the analyses.Mixed models for each of the quality-of-life scores were performed to investigate changes in QoL over time, treating patient and centre as random effects, and QoL scores at baseline, time, treatment and interaction of treatment and time as fixed effects.Subgroup analysis to investigate the effect of the intervention among NMES + SET + BMT, NMES + BMT, SET + BMT and BMT was performed. Seven subgroup analyses were performed in the intention-to-treat (ITT) population for the primary outcome (AWD), measured at 3 months using Tobit regression models, five were originally described in the SAP and two were added later as post-hoc analyses.A post-hoc analysis was performed with baseline AWD divided into short, medium and long distances (<25 per cent, 25–75 per cent and >75 per cent, respectively). For each stratum a Tobit regression for the transformed right-censored AWD at 3 months was performed.All analyses were performed on an ITT basis with STATA software, version 17 (StataCorp), with statistical significance set at a two-sided alpha level of 5 per cent.