Early participant attrition from clinical trials: role of trial design and logistics
Early participant attrition from clinical trials: role of trial design and logistics
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DOI：
10.1177/1740774508094406
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发表时间：
2008-01-01
期刊：
影响因子：
2.7
通讯作者：
Given, Barbara
中科院分区：
文献类型：
--
作者：
Siddiqi, Azfar-e-Alam;Sikorskii, Alla;Given, Barbara
研究背景随机对照试验的受试者自然减员降低了研究的统计能力，并有可能引入偏见。及早发现潜在的损耗原因有助于减少病人的损耗。我们对两个涉及癌症患者的试验进行了二次分析，目的是在两个临床试验的两个早期阶段，即从同意到筛查(第一阶段)和从筛查到入院访谈(第二阶段)，确定磨耗的预测因素。在每项试验中，认知行为干预与心理教育干预的益处进行了比较，以帮助患者管理癌症和治疗相关症状。结果在885名应征者中，785人完成了筛查，782人符合条件，713人完成了入院面试。在第一阶段，同意和首次接触之间的延迟更长，患者教育水平较低，少数族裔，以及较长的筛查持续时间增加了退出的可能性，对少数族裔的影响明显强于白人患者。在第二阶段，低教育程度、少数族裔、较长的筛查延迟以及症状严重程度对生活享受的影响显著增加了磨耗的可能性。限制参与者报告的磨损原因没有建模；然而，排除在研究期间死亡的患者意味着大多数离开研究的患者都做出了有意识的决定。结论为了确保外部有效性的保持，同意和随机进入试验之间的时间必须保持在最低限度。接触和及时运行之间的延迟，可能包括对患者进行筛查，以确保他们将从试验中受益，必须在减员率之间进行权衡。压缩联系人之间的间隔对于留住少数族裔尤为重要。
Background Participant attrition from randomized controlled trials reduces the statistical power of the study and can potentially introduce bias. Early identification of potential causes of attrition can help reduce patient attrition. We performed secondary analyses of two trials involving cancer patients.Purpose To identify predictors of attrition during two early phases, i.e., from consent to screening (Phase-1), and from screening to intake interview (Phase-2) in two clinical trials.Methods Cancer patients undergoing chemotherapy were asked to enroll in one of two clinical trials. In each trial the benefits of a cognitive behavioral intervention were compared with a psycho-educational intervention to assist patients to manage cancer and treatment-related symptoms. Following consent patients were screened for their symptoms' severity to determine their eligibility.Results Of the 885 consenters 785 completed screening and of the 782 eligible for participation, 713 completed intake interview. In the first phase, longer delays between consent and first contact attempt, lower levels of patient education, minority race, and prolonged duration of screening increased the likelihood of dropping out with a significantly stronger effect on minorities than white patients. In the second phase, low education, being a minority, longer screening delays, and impact of symptom severity on enjoyment of life significantly increased probability of attrition. Limitations Participant reported causes of attrition were not modeled; however, exclusion of patients who died during the time period of this research meant that most patients leaving the study made a conscious decision to do so.Conclusions To assure preservation of external validity, the time between consent and randomization into the arms of a trial must be held to a minimum. Delays between contacts and run in time, that may include screening patients to assure they will benefit from a trial, must be balanced against rates of attrition. Compressing intervals between contacts is particularly important to retain minorities.