• analgesia
• Anesthesia, Local
• Nerve Block

By conducting a prospective randomised open-label non-inferiority trial in 90 patients who underwent elective unilateral video-assisted lobectomy or wedge resection, van den Broek et al1 compared the effects of adding continuous erector spinae plane block and thoracic epidural analgesia into a multimodal analgesia regimen on the quality of postoperative recovery assessed by the Quality of Recovery-15 questionnaire (QoR-15). In the sample size calculation, they described that a non-inferiority limit of 13 was assumed according to the previous work of Myles et al in 2016.2 We noted that this value was actually the absolute mean change in the QoR-15 score when the postoperative recovery health status rated by patients achieved a classification of minimal change rather than the minimal clinically important difference (MCID) of the QoR-15 score. When comparing the clinical utility of different interventions in a randomised controlled trial, the MCID is often used to determine the smallest between-group difference that the primary outcome must change to be meaningful to the patient.3 For a non-inferiority randomised controlled trial, the MCID should be selected as the assumed non-inferiority limit of the primary outcome. In the original work of Myles et al,2 the MCID of the QoR-15 score is actually demonstrated to be eight points. In 2021, Myles et al4 have re-evaluated the MCID of the QoR-15 score and updated it to a difference of six points. We are concerned that using a non-inferiority limit of more than six points would have underestimated the sample size of this study. This design limitation may not change the main findings of den Broek et al’s study, but clarifying this issue would improve the transparency of the research design.

According to the QoR-15 score, the quality of postoperative recovery is generally classified as excellent (>135), good (122–134), moderate (90–121) and poor (<90).5 In this study, the QoR15 scores on postoperative day 2 were 114±30 in the erector spinae plane block group and 116±24 in the thoracic epidural analgesia group, respectively. These results indicate that a significant proportion of patients in the two groups did not achieve an excellent or good quality of postoperative recovery on postoperative day 2. For patients undergoing elective unilateral video-assisted thoracoscopic surgery in the context of current enhanced recovery after surgery practices; thus, we argue that the real clinical values of incorporating a continuous erector spinae plane block and a thoracic epidural analgesia into the multimodal analgesia regimens deserve further research.