Department of Surgery, Loma Linda Veterans Affairs Healthcare System, Loma Linda, California.
Department of Medical Affairs, MiMedx Group, Inc., Marietta, Georgia.
Int Wound J. 2019 Jun;16(3):761-767. doi: 10.1111/iwj.13094. Epub 2019 Mar 12.
Statistical interpretation of data collected in a randomised controlled trial (RCT) is conducted on the intention-to-treat (ITT) and/or the per-protocol (PP) study populations. ITT analysis is a comparison of treatment groups including all patients as originally allocated after randomisation regardless if treatment was initiated or completed. PP analysis is a comparison of treatment groups including only those patients who completed the treatment as originally allocated, although it is often criticised because of its potential to instil bias. A previous report from an RCT conducted to evaluate the efficacy of dehydrated human amnion/chorion membrane allograft (EpiFix) as an adjunct to standard comprehensive wound therapy consisting of moist dressings and multi-layer compression in the healing of venous leg ulcers (VLUs) only reported PP study results (n = 109, 52 EpiFix and 57 standard care patients), although there were 128 patients randomised: 64 to the EpiFix group and 64 to the standard care group. Primary study outcome was the incidence of healing at 12 weeks. The purpose of the present study is to report ITT results on all 128 randomised subjects and assess if both ITT and PP data analyses arrive at the same conclusion of the efficacy of EpiFix as a treatment for VLU. Rates of healing for the ITT and PP populations were, respectively, 50% and 60% for those receiving EpiFix and 31% and 35% for those in the standard care cohort. Within both ITT and PP analyses, these differences were statistically significant; P = 0.0473, ITT and P = 0.0128, PP. The Kaplan-Meier plot of time to heal within 12 weeks for the ITT and PP populations demonstrated a superior wound-healing trajectory for EpiFix compared with VLUs treated with standard care alone. These data provide clinicians and health policymakers an additional level of assurance regarding the effectiveness of EpiFix.
对随机对照试验（RCT）中收集的数据进行统计解释时，通常会基于意向治疗（ITT）和/或符合方案（PP）人群进行分析。ITT 分析是对治疗组的比较，包括所有随机分组后最初接受分配治疗的患者，无论是否开始或完成治疗。PP 分析是对治疗组的比较，仅包括那些完成最初分配治疗的患者，尽管它经常受到批评，因为它可能会引入偏倚。此前一项 RCT 报告评估了脱水人羊膜/绒毛膜同种异体移植物（EpiFix）作为湿性敷料和多层压缩标准综合伤口治疗的辅助治疗在静脉溃疡（VLU）愈合中的疗效，仅报告了 PP 研究结果（n=109，52 例 EpiFix 和 57 例标准护理患者），尽管有 128 例患者随机分组：64 例分入 EpiFix 组，64 例分入标准护理组。主要研究结局是 12 周时的愈合发生率。本研究旨在报告所有 128 例随机患者的 ITT 结果，并评估 ITT 和 PP 数据分析是否得出 EpiFix 治疗 VLU 疗效相同的结论。ITT 和 PP 人群中分别接受 EpiFix 治疗的患者愈合率为 50%和 60%，而接受标准护理的患者愈合率为 31%和 35%。在 ITT 和 PP 分析中，这些差异均具有统计学意义；P=0.0473，ITT 和 P=0.0128，PP。ITT 和 PP 人群中 12 周内愈合的 Kaplan-Meier 图显示，与单独接受标准护理治疗的 VLUs 相比，EpiFix 具有更好的伤口愈合轨迹。这些数据为临床医生和卫生政策制定者提供了关于 EpiFix 有效性的额外保证。
