1 Department of Surgery, Northwestern University , Chicago, Illinois.
2 Department of Obstetrics and Gynecology, Northwestern University , Chicago, Illinois.
J Womens Health (Larchmt). 2018 Nov;27(11):1342-1348. doi: 10.1089/jwh.2017.6873. Epub 2018 Oct 10.
Prior studies have shown that sex bias exists with subject enrollment in clinical trials, with more men being enrolled than women. The objective of this study was to identify if sex bias continues to exist in present day clinical trials entered into ClinicalTrials.gov . We hypothesize that males and females are not equally represented in recent clinical trials.
Data were abstracted from all interventional Phase I, II, and III clinical trials with adult subjects entered into ClinicalTrials.gov from January 1, 2011 to December 31, 2013 and completed by November 30, 2015. Number and sex of subjects, funding source, allocation, end point classification, interventional model, and purpose were recorded. Studies pertaining to diseases that were sex specific were excluded.
Of 1,668 studies included in the initial search, 167 were excluded due to sex-specific study topic. Of the remaining 1,501 studies, 177,656 (51.1%) male and 170,331 (49.0%) female subjects were included. There was a significant difference in the sex of the subjects included in Phase I (64.1% male/35.9% female), Phase II (48.4% male/51.6% female), and Phase III (51.0% male/49.1% female) clinical trials (p < 0.05). Similarly, there was a significant difference in the sex of the subjects included in industry (50.7% male/49.3% female), National Institutes of Health (NIH) (56.6% male/43.4% female), "Other US Federal" (62.5% male/37.5% female), and "Other" funded (53.4% male/46.6% female) clinical trials (p < 0.0001), as well as between randomized (50.5% male/49.6% female) and nonrandomized (54.8% male/45.2% female) clinical trials (p < 0.0001). Upon evaluating if the sex of the subjects included in the individual clinical trials was equally matched, we found that only 4.1% of clinical trials had 100% sex matching, 22.2% had 80% sex matching, and 56.5% had 50% sex matching. Using a liberal 50% sex-matching criteria, Phase III and II clinical trials matched the sex of the subjects more frequently compared to Phase I trials (60.8%, 57.8%, and 45.5%, respectively, p = 0.003).
These data reveal that sex bias is present in current day clinical trials. Despite legislation requiring NIH-funded clinical trials to include women, NIH-funded trials were not better than industry-funded trials at matching the inclusion of both sexes.
先前的研究表明，临床试验中的受试者入组存在性别偏见，男性入组人数多于女性。本研究的目的是确定当今在 ClinicalTrials.gov 中入组的临床试验中是否仍然存在性别偏见。我们假设男性和女性在最近的临床试验中没有得到平等代表。
从 2011 年 1 月 1 日至 2013 年 12 月 31 日期间在 ClinicalTrials.gov 中入组的所有成人受试者的干预性 I 期、II 期和 III 期临床试验中提取数据，并于 2015 年 11 月 30 日完成。记录受试者数量和性别、资金来源、分配、终点分类、干预模式和目的。排除与性别特异性疾病相关的研究。
在最初的搜索中，纳入了 1668 项研究，其中 167 项由于研究主题的性别特异性而被排除。在剩余的 1501 项研究中，纳入了 177656 名（51.1%）男性和 170331 名（49.0%）女性受试者。I 期（64.1%男性/35.9%女性）、II 期（48.4%男性/51.6%女性）和 III 期（51.0%男性/49.1%女性）临床试验中受试者的性别存在显著差异（p<0.05）。同样，在工业界（50.7%男性/49.3%女性）、美国国立卫生研究院（NIH）（56.6%男性/43.4%女性）、“其他美国联邦”（62.5%男性/37.5%女性）和“其他”资助（53.4%男性/46.6%女性）临床试验中受试者的性别存在显著差异（p<0.0001），以及随机（50.5%男性/49.6%女性）和非随机（54.8%男性/45.2%女性）临床试验中（p<0.0001）。在评估个体临床试验中纳入的受试者性别是否匹配时，我们发现只有 4.1%的临床试验达到了 100%的性别匹配，22.2%的临床试验达到了 80%的性别匹配，56.5%的临床试验达到了 50%的性别匹配。使用宽松的 50%性别匹配标准，III 期和 II 期临床试验比 I 期临床试验更频繁地匹配受试者的性别（分别为 60.8%、57.8%和 45.5%，p=0.003）。
这些数据表明，目前的临床试验中存在性别偏见。尽管立法要求 NIH 资助的临床试验纳入女性，但 NIH 资助的试验在匹配两性受试者入组方面并不优于工业界资助的试验。
