Department of Surgery, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
Br J Surg. 2017 Apr;104(5):562-569. doi: 10.1002/bjs.10448. Epub 2017 Feb 27.
RCTs are the standard for assessing medical interventions, but they may not be feasible and their external validity is sometimes questioned. This study aimed to compare results from an RCT on mesenteric defect closure during laparoscopic gastric bypass with those from a national database containing data on the same procedure, to shed light on the external validity of the RCT.
Patients undergoing laparoscopic gastric bypass surgery within an RCT conducted between 1 May 2010 and 14 November 2011 were compared with those who underwent the same procedure in Sweden outside the RCT over the same time interval. Primary endpoints were severe complications within 30 days and surgery for small bowel obstruction within 4 years.
Some 2507 patients in the RCT were compared with 8485 patients in the non-RCT group. There were no differences in severe complications within 30 days in the group without closure of the mesenteric defect (odds ratio (OR) for RCT versus non-RCT 0·94, 95 per cent c.i. 0·64 to 1·36; P = 0·728) or in the group with closure of the defect (OR 1·34, 0·96 to 1·86; P = 0·087). There were no differences between the RCT and non-RCT cohorts in reoperation rates for small bowel obstruction in the mesenteric defect non-closure (cumulative incidence 10·9 versus 9·4 per cent respectively; hazard ratio (HR) 1·20, 95 per cent c.i. 0·99 to 1·46; P = 0·065) and closure (cumulative incidence 5·7 versus 7·0 per cent; HR 0·82, 0·62 to 1·07; P = 0·137) groups. The relative risk for small bowel obstruction without mesenteric defect closure compared with closure was 1·91 in the RCT group and 1·39 in the non-RCT group.
The efficacy of mesenteric defect closure was similar in the RCT and national registry, providing evidence for the external validity of the RCT.
RCT 是评估医学干预措施的标准，但它们可能不可行，其外部有效性有时也受到质疑。本研究旨在比较腹腔镜胃旁路手术中肠系膜缺陷闭合的 RCT 结果与同一时期全国数据库中包含相同手术数据的结果，以阐明 RCT 的外部有效性。
将 2010 年 5 月 1 日至 2011 年 11 月 14 日进行的 RCT 中接受腹腔镜胃旁路手术的患者与同一时期 RCT 之外瑞典接受相同手术的患者进行比较。主要终点是 30 天内严重并发症和 4 年内小肠梗阻手术。
在 RCT 中纳入了 2507 例患者，在非 RCT 组中纳入了 8485 例患者。在未闭合肠系膜缺陷的组中（RCT 与非 RCT 的比值比（OR）为 0.94，95%置信区间（CI）为 0.64 至 1.36；P=0.728）或在闭合缺陷的组中（OR 为 1.34，0.96 至 1.86；P=0.087），30 天内严重并发症发生率无差异。在肠系膜缺陷未闭合（累积发生率分别为 10.9%和 9.4%；风险比（HR）为 1.20，95%CI 为 0.99 至 1.46；P=0.065）和闭合（累积发生率分别为 5.7%和 7.0%；HR 为 0.82，0.62 至 1.07；P=0.137）组中，RCT 组和全国登记处之间的小肠梗阻再手术率也无差异。与闭合相比，肠系膜缺陷未闭合的小肠梗阻的相对风险在 RCT 组为 1.91，在非 RCT 组为 1.39。
在 RCT 和全国登记处中，肠系膜缺陷闭合的疗效相似，为 RCT 的外部有效性提供了证据。
