Regional Health Authority of Umbria, via Mario Angeloni 61, 06123 Perugia, Italy.
BMJ. 2010 Jun 14;340:c2697. doi: 10.1136/bmj.c2697.
To determine the incidence and characteristics of randomised controlled trials that report using the modified intention to treat approach, and how the approach is described.
Systematic review.
PubMed, Embase, Cochrane central register of controlled trials, ISI Web of Knowledge, Ovid, HighWire Press, Science-Direct, Ingenta, Medscape, BioMed Central, Springer, and Wiley, from inception to December 2006.
Incidence of trials in which use of modified intention to treat was reported, and how the approach was described (classified according to the type and number of deviations from the intention to treat approach).
475 randomised controlled trials reported use of a modified intention to treat analysis. Of these, 76 (16%) were published in five highly cited general medical journals. The incidence of all trials that reported use of modified intention to treat published in journals indexed in Medline increased from 0.006% in 1982-6 to 0.5% in 2002-6 (P<0.001 for linear trend). When the description of the modified intention to treat was examined in each trial, 192 (40%) reported one type of deviation from the intention to treat approach, 261 (55%) reported two or more types, and 22 (5%) did not describe any type. In 266 (56%) of the trials the deviation was related to the treatment received, in 196 (41%) to a post baseline assessment, in 118 (25%) to a baseline assessment, in 108 (23%) to a target condition, and in 23 (5%) to follow-up. Post-randomisation exclusions occurred in 380 (80%) trials. The results reported by 270 of the 352 (77%) superiority trials favoured the drug under investigation. All of the 123 trials using equivalence or non-inferiority methods to investigate interventions reported results that favoured their assumptions.
Randomised controlled trials that report using a modified intention to treat are increasingly being published in the medical literature. The descriptions of such an approach were ambiguous, and may cover any type of descriptions for exclusion, such as missing data and deviation from protocol. Explicit statements about post-randomisation exclusions should replace the ambiguous terminology of modified intention to treat.
确定报告采用改良意向治疗方法的随机对照试验的发生率和特征，以及该方法的描述方式。
系统评价。
PubMed、Embase、Cochrane 对照试验中心注册库、ISI Web of Knowledge、Ovid、HighWire Press、Science-Direct、Ingenta、Medscape、BioMed Central、Springer 和 Wiley，从开始到 2006 年 12 月。
报告采用改良意向治疗分析的试验发生率，以及该方法的描述方式（根据与意向治疗方法的偏离类型和数量进行分类）。
475 项随机对照试验报告采用了改良意向治疗分析。其中，5 种高引用的普通医学期刊发表了 76 项（16%）。报告采用改良意向治疗分析的试验中，在 Medline 索引期刊上发表的所有试验的发生率从 1982-6 年的 0.006%增加到 2002-6 年的 0.5%（线性趋势 P<0.001）。当检查每个试验中改良意向治疗的描述时，192 项（40%）报告了一种与意向治疗方法的偏离，261 项（55%）报告了两种或两种以上类型，22 项（5%）没有描述任何类型。在 266 项（56%）试验中，偏离与接受的治疗有关，196 项（41%）与基线后评估有关，118 项（25%）与基线评估有关，108 项（23%）与目标条件有关，23 项（5%）与随访有关。在 380 项（80%）试验中发生了随机后排除。在 352 项（77%）优效性试验中，有 270 项报告的结果有利于所研究的药物。所有 123 项采用等效或非劣效性方法研究干预措施的试验均报告了有利于其假设的结果。
报告采用改良意向治疗的随机对照试验越来越多地发表在医学文献中。这种方法的描述不明确，可能涵盖任何类型的排除描述，如缺失数据和偏离方案。关于随机后排除的明确声明应替代改良意向治疗的模糊术语。
