Cook Ryan, Quinn Brendan, Heinzerling Keith, Shoptaw Steve
Department of Epidemiology, Los Angeles Fielding School of Public Health, University of California, Los Angeles, CA, USA.
Departments of Family Medicine and Psychiatry and Biobehavioral Science, Los Angeles David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
Addiction. 2017 Jun;112(6):1077-1085. doi: 10.1111/add.13765. Epub 2017 Feb 16.
High rates of loss to follow-up represent a significant challenge to clinical trials of pharmacological treatments for methamphetamine (MA) use disorder. We aimed to estimate and test the relationship between achieving and maintaining abstinence in the initial weeks of study participation and subsequent retention in such trials, hypothesizing that participants able to achieve early abstinence would be less likely to drop out.
Data from four randomized controlled trials (RCTs) of pharmacological treatments for MA use disorder were pooled and analyzed using a random-effects approach.
All trials were conducted in the greater Los Angeles, CA, USA area.
A total of 440 participants were included; trials were conducted between 2004 and 2014.
Participants' ability to achieve a brief period of initial abstinence was measured as the number of MA-negative urine screens completed in the first 2 weeks of the trials. Outcomes were the likelihood of dropout, i.e. missing two consecutive weeks of scheduled urine drug screens, and the number of days participants were retained in the trials.
Study participants achieved an average of three (of six possible) negative urine screens during the first 2 weeks of the trials, 51% dropped out and the average number of days retained was 60 (of 90 maximum). Each additional negative urine screen achieved during the first 2 weeks of the study reduced multiplicatively the odds of dropout by 41% [odds ratio (OR) = 0.59, 95% confidence interval (CI) = 0.53, 0.66]. Abstinence was also a significant predictor of retention time; the hazard ratio for non-completion was 0.75 per additional negative urine screen (95% CI = 0.71, 0.80).
Participants in randomized controlled trials of pharmacological treatments for methamphetamine use disorder who are able to achieve a brief period of early abstinence are retained longer in the trials and are less likely to drop out overall.
高失访率对甲基苯丙胺（MA）使用障碍药物治疗的临床试验构成了重大挑战。我们旨在评估并检验在研究参与的最初几周内实现并维持戒断与后续此类试验中的留存率之间的关系，假设能够实现早期戒断的参与者退出试验的可能性较小。
对四项MA使用障碍药物治疗的随机对照试验（RCT）数据进行汇总，并采用随机效应方法进行分析。
所有试验均在美国加利福尼亚州大洛杉矶地区进行。
共纳入440名参与者；试验于2004年至2014年期间进行。
参与者在试验前两周内完成的MA阴性尿液筛查数量被用作衡量其实现短期初始戒断能力的指标。结果指标为退出试验的可能性，即连续两周错过预定尿液药物筛查，以及参与者在试验中的留存天数。
研究参与者在试验的前两周内平均完成了（可能的六项中的）三项阴性尿液筛查，51%的参与者退出试验，平均留存天数为60天（最多90天）。在研究的前两周内每多完成一项阴性尿液筛查，退出试验的几率就会成倍降低41%[优势比（OR）=0.59，95%置信区间（CI）=0.53，0.66]。戒断也是留存时间的一个重要预测因素；每多一项阴性尿液筛查，未完成试验的风险比为0.75（95%CI=0.71，0.80）。
在甲基苯丙胺使用障碍药物治疗的随机对照试验中，能够实现短期早期戒断的参与者在试验中的留存时间更长，总体退出试验的可能性更小。
