Abenhaim Haim A, Tremblay Valerie, Tremblay Lise, Audibert Francois
Department of Obstetrics and Gynecology, Université de Montréal, 3175, Côte-Sainte-Catherine, Montreal, Quebec, Canada.
J Perinat Med. 2007;35(4):301-4. doi: 10.1515/JPM.2007.083.
Nifedipine is believed to be a superior tocolytic agent on the basis of efficacy and side-effect profile, but was never prospectively evaluated in a placebo-controlled randomized clinical trial (RCT). In our study, we sought to identify limitations in participation for a would-be RCT comparing nifedipine to placebo.
A prospective feasibility study was conducted at Ste-Justine Hospital, a tertiary care center, on women between 24 and 34 weeks' gestation, presenting to the labor and delivery room with obstetrical complaints. Patient information was collected and would-be participants were identified on the basis of pre-established clinical and ultrasound criteria as well as on willingness to participate, as determined by the study research nurse.
During a 6-month period, 483 women presenting with signs and symptoms of preterm labor (PTL) were eligible for further evaluation. A total of 321 (66.5%) women were excluded for obstetrical and medical reasons whereas 125 (25.9%) did not meet strict inclusion criteria (cervical length <25 mm or positive fetal fibronectin). When using strict criteria, only 37 women (7.6%) were found to be eligible for study participation. Subject willingness to participate as assessed by the research nurse was 50%.
If adhering to strict inclusion/exclusion criteria, the feasibility of an appropriately sampled RCT testing tocolytic therapy against a placebo would require a large concerted multicenter effort to meet sample size demands.
基于疗效和副作用情况，硝苯地平被认为是一种更优的宫缩抑制剂，但从未在安慰剂对照的随机临床试验（RCT）中进行过前瞻性评估。在我们的研究中，我们试图确定一项比较硝苯地平与安慰剂的潜在RCT研究在受试者招募方面的局限性。
在三级护理中心圣贾斯汀医院对妊娠24至34周、因产科问题前往产房就诊的女性进行了一项前瞻性可行性研究。收集患者信息，并由研究护士根据预先确定的临床和超声标准以及参与意愿来确定潜在受试者。
在6个月期间，483名出现早产迹象和症状的女性符合进一步评估条件。共有321名（66.5%）女性因产科和医学原因被排除，而125名（25.9%）不符合严格的纳入标准（宫颈长度<25 mm或胎儿纤维连接蛋白阳性）。使用严格标准时，仅发现37名女性（7.6%）符合研究参与条件。研究护士评估的受试者参与意愿为50%。
如果坚持严格的纳入/排除标准，针对安慰剂进行宫缩抑制治疗的适当抽样RCT研究的可行性将需要大量协调一致的多中心努力以满足样本量需求。
