Johnson B F, Hamilton G, Fink J, Lucey G, Bennet N, Lew R
Department of Medicine, University of Massachusetts Medical School, Worcester, USA.
Control Clin Trials. 2000 Feb;21(1):62-72. doi: 10.1016/s0197-2456(99)00049-5.
The Potassium Adherence Clinical Trial (PACT) incorporates one randomized clinical trial within another. A randomized trial of interventions to increase adherence to medication is nested within a second randomized clinical trial testing hypotensive effect of supplemental oral potassium. The trial aims principally to compare the effects of three intervention strategies: two sessions of individual patient counseling, two telephone contacts, or standard care. The trial aims secondarily to evaluate the effect of 60 mEq supplemental oral potassium daily on sitting systolic and diastolic blood pressure in hypertensive patients on established drug therapy. Therefore, it organizes the patients given potassium into three study groups for adherence interventions, and the patients assigned to placebo into a further three. We evaluate adherence primarily by means of the Medication Event Monitoring System (MEMS), an electronic system that records the date and time that the container of study medication is opened. Additional measurements, such as assessments of change in levels of urinary potassium, pill counts, appointment records, self-reporting by patients, and estimates by physician of adherence, are used and correlated with MEMS data. At a single center, the trial enrolled 107 participants between the ages of 26 and 80. This paper describes the background to this trial within a trial, details its design, documents the baseline characteristics of participants enrolled, and describes issues experienced during implementation of the trial.
钾依从性临床试验（PACT）在另一个试验中纳入了一项随机临床试验。一项旨在提高药物依从性的干预措施随机试验嵌套在第二项测试口服补充钾降压效果的随机临床试验中。该试验主要目的是比较三种干预策略的效果：两次患者个体咨询、两次电话联系或标准护理。其次要目的是评估每日60毫当量口服补充钾对接受既定药物治疗的高血压患者坐位收缩压和舒张压的影响。因此，它将接受钾治疗的患者分为三个研究组进行依从性干预，将分配到安慰剂组的患者再分为三个组。我们主要通过药物事件监测系统（MEMS）评估依从性，这是一个记录研究药物容器打开日期和时间的电子系统。还采用了其他测量方法，如评估尿钾水平变化、药丸计数、预约记录、患者自我报告以及医生对依从性的估计，并将其与MEMS数据相关联。在单一中心，该试验招募了107名年龄在26至80岁之间的参与者。本文描述了这个试验中之试验的背景，详细介绍了其设计，记录了所招募参与者的基线特征，并描述了试验实施过程中遇到的问题。
