Cramer J A, Collins J F, Mattson R H
Epilepsy Center, Epilepsy Cooperative Study, VA Medical Center, West Haven, Connecticut 06516.
Control Clin Trials. 1988 Mar;9(1):47-63. doi: 10.1016/0197-2456(88)90008-6.
Many patients entering a long-term clinical study are unable to remain active in the trial (taking medication as prescribed and attending clinic as scheduled) for up to 6 years. We studied a group of 622 patients entering an antiepileptic drug study with maximum possible follow-up period of 6 years. A centralized case validation system was used in this VA Epilepsy Cooperative Study to note problems in patients entering the study. The categories established for pre-entry case status were associated with events occurring during the course of the study that led to noncompletion of the study. The data were reviewed to determine whether pre-entry status can be used to suggest the likelihood that an individual patient will remain in the study to completion or become a non-drug-related loss. Over one-half of all losses were related to failure to return to clinic. Medical problems (18%), medication noncompliance (14%), and psychiatric problems (12%) accounted for the remainder of losses. Pre-entry issues often were the same reason for early loss. However, many patients with problems known at entry were maintained in the study when targeted for extra support. We found some groups of patients had considerably more early terminations whereas others had less loss to the trial than we predicted originally. Thus, case categorization at entry can be used to estimate the likelihood of early termination from a clinical trial.
许多进入长期临床研究的患者在长达6年的时间里无法持续积极参与试验（按规定服药并按时就诊）。我们研究了一组622名进入抗癫痫药物研究的患者，其最长随访期为6年。在这项退伍军人事务部癫痫合作研究中，使用了一个集中的病例验证系统来记录进入研究的患者中存在的问题。为入组前病例状态设定的类别与研究过程中发生的导致研究未完成的事件相关。对数据进行了审查，以确定入组前状态是否可用于提示个体患者完成研究或成为与药物无关的失访对象的可能性。所有失访病例中超过一半与未返回诊所有关。医疗问题（18%）、药物治疗不依从（14%）和精神问题（12%）占其余的失访原因。入组前的问题往往是早期失访的相同原因。然而，许多入组时已知存在问题的患者在获得针对性额外支持后仍留在研究中。我们发现，有些患者组的早期终止率相当高，而另一些患者组的失访率比我们最初预测的要低。因此，入组时的病例分类可用于估计临床试验早期终止的可能性。
