Scheim David E, Aldous Colleen, Osimani Barbara, Fordham Edmund J, Hoy Wendy E
US Public Health Service, Commissioned Corps, Inactive Reserve, Blacksburg, VA 24060, USA.
College of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
J Clin Med. 2023 May 23;12(11):3625. doi: 10.3390/jcm12113625.
Under exceptional circumstances, including high rates of protocol non-compliance, per-protocol (PP) analysis can better indicate the real-world benefits of a medical intervention than intention-to-treat (ITT) analysis. Exemplifying this, the first randomized clinical trial (RCT) considered found that colonoscopy screenings were marginally beneficial, based upon ITT analysis, with only 42% of the intervention group actually undergoing the procedure. However, the study authors themselves concluded that the medical efficacy of that screening was a 50% reduction in colorectal cancer deaths among that 42% PP group. The second RCT found a ten-fold reduction in mortality for a COVID-19 treatment drug vs. placebo by PP analysis, but only a minor benefit by ITT analysis. The third RCT, conducted as an arm of the same platform trial as the second RCT, tested another COVID-19 treatment drug and reported no significant benefit by ITT analysis. Inconsistencies and irregularities in the reporting of protocol compliance for this study required consideration of PP outcomes for deaths and hospitalizations, yet the study coauthors refused to disclose them, instead directing inquiring scientists to a data repository which never held the study's data. These three RCTs illustrate conditions under which PP outcomes may differ significantly from ITT outcomes and the need for data transparency when these reported or indicated discrepancies arise.
在特殊情况下,包括方案不依从率较高时,与意向性分析(ITT)相比,符合方案(PP)分析能更好地表明医学干预在现实世界中的益处。举例来说,所考虑的第一项随机临床试验(RCT)发现,基于ITT分析,结肠镜筛查仅有边际效益,干预组中只有42%的人实际接受了该检查。然而,研究作者自己得出结论,在那42%的符合方案组中,该筛查的医学疗效是结直肠癌死亡人数减少了50%。第二项RCT通过PP分析发现一种治疗新冠肺炎的药物与安慰剂相比死亡率降低了十倍,但通过ITT分析仅显示有微小益处。第三项RCT作为与第二项RCT相同平台试验的一个分支进行,测试了另一种治疗新冠肺炎的药物,通过ITT分析报告无显著益处。该研究方案依从性报告中的不一致和违规情况需要考虑PP分析得出的死亡和住院结果,但研究共同作者拒绝披露这些结果,而是指示询问的科学家去一个从未保存该研究数据的数据存储库查找。这三项RCT说明了PP分析结果可能与ITT分析结果存在显著差异的情况,以及当出现这些报告的或显示的差异时数据透明的必要性。