Department of Primary Care and General Practice, Clinical Sciences Building, University of Birmingham, Birmingham B15 2TT, UK.
Fam Pract. 2010 Dec;27(6):691-7. doi: 10.1093/fampra/cmq050. Epub 2010 Jul 7.
recruitment targets to randomized controlled trials (RCTs) are often not met. Many interventions are used to improve recruitment but there is little empirical evidence on whether these approaches work.
to examine whether changes to the design and conduct of a primary care-based RCT were associated with changes in patient recruitment.
an observational time series analysis of recruitment to a primary care-based multi-centre RCT of aspirin versus warfarin for stroke prevention, which involved 330 practices. Several changes to the trial protocol and procedures were made over the 4 years of patient recruitment. For each quarter throughout the recruitment period, the recruitment rate per 1000 total population in active practices was calculated.
the recruitment target of 930 patients was exceeded. Fluctuations in recruitment rate occurred during the recruitment period. Following protocol changes aimed to reduce clinical workload, there was a significant increase in recruitment during the final 6 months of the study, during a period when there was not a similarly large increase in the total population available.
these findings suggest that the conduct of a trial is an important consideration if studies are to recruit successfully. Expanding the number of centres may not be the most effective way to improve recruitment.
随机对照试验（RCT）的招募目标往往无法实现。许多干预措施被用于改善招募情况，但关于这些方法是否有效的实证证据很少。
检验对基于初级保健的 RCT 的设计和实施进行更改是否与患者招募的变化相关。
对一项基于初级保健的多中心 RCT 的观察性时间序列分析，该 RCT 比较了阿司匹林与华法林预防中风的效果，涉及 330 个实践。在患者招募的 4 年中，对试验方案和程序进行了多项更改。在招募期间的每个季度，计算活跃实践中每 1000 总人口的招募率。
超过了 930 名患者的招募目标。招募率在招募期间出现波动。在旨在降低临床工作量的方案更改之后，在研究的最后 6 个月期间，招募人数显著增加，而在此期间，可用于研究的总人数并没有同样大幅增加。
这些发现表明，如果要成功招募研究对象，那么试验的实施是一个重要的考虑因素。扩大中心数量可能不是提高招募效果的最有效方法。
