“均数的标准差”？

Freeman et al conducted another RCT in South Australia to assess the efficacy and safety of IDET for the management of internal disc disruption in the lumbar spine [9]. Fifty- seven patients met inclusion criteria including symptoms of LBP of at least 3 months, evidence of degenerative disc disease on MRI, and presence of one- or two-level symptomatic disc degeneration as determined by provocative discography. Successful outcome was defined meeting all the following criteria: no neurologic deficit resulting from the procedure, an improvement in the Low Back Pain Outcome Score (LBOS) of 7 or more points, and an improvement in the Short-Form 36 General Health questionnaire (Australian version SF-36) subscales of bodily pain and physical functioning of greater than 1 standard deviation from the mean.At 6 months follow-up, no subject in either group met criteria for successful outcome. The authors concluded that the IDET procedure appeared safe with no permanent complications and that there was no significant benefit from IDET over placebo.

为评估椎间盘内电热疗法治疗腰椎内椎间盘破裂的有效性和安全性，Freeman等人在南澳大利亚进行了另一项随机对照研究^[9]。57名患者符合纳入标准，标准包括至少3个月的腰痛症状、MRI显示退行性椎间盘疾病的证据、以及通过激发性椎间盘造影术确定有1或2节段症状性椎间盘退变。成功的预后被定义为符合以下所有标准：术后神经功能障碍消失、腰痛预后评分改善≥7分，以及Short-Form 36一般健康问卷（澳大利亚版SF-36）身体疼痛和身体功能的分量表的改善超过1个标准差。在6个月的随访中，两组受试者都没有达到成功预后的标准。研究者总结说，椎间盘内电热疗法似乎是安全的， 没有永久性的并发症，但与对照组相比没有明显的益处。

各位老师，standard deviation from the mean“均数的标准差”，有没有必要把“均数的”再说一遍？除了“均数”，还有别的也有“标准差”吗？统计学的不好