DeKosky Steven T, Fitzpatrick Annette, Ives Diane G, Saxton Judith, Williamson Jeff, Lopez Oscar L, Burke Gregory, Fried Linda, Kuller Lewis H, Robbins John, Tracy Russell, Woolard Nancy, Dunn Leslie, Kronmal Richard, Nahin Richard, Furberg Curt
Department of Neurology, University of Pittsburgh, 3471 Fifth Avenue, Suite 811, Pittsburgh, PA 15213, USA.
Contemp Clin Trials. 2006 Jun;27(3):238-53. doi: 10.1016/j.cct.2006.02.007. Epub 2006 Apr 19.
The epidemic of late life dementia, prominence of use of alternative medications and supplements, and initiation of efforts to determine how to prevent dementia have led to efforts to conduct studies aimed at prevention of dementia. The GEM (Ginkgo Evaluation of Memory) study was initially designed as a 5-year, randomized double-blind, placebo-controlled trial of Ginkgo biloba, administered in a dose of 120 mg twice per day as EGb761, in the prevention of dementia (and especially Alzheimer's disease) in normal elderly or those with mild cognitive impairment. The study anticipates 8.5 years of participant follow-up. Initial power calculations based on estimates of incidence rates of dementia in the target population (age 75+) led to a 3000-person study, which was successfully recruited at four clinical sites around the United States from September 2000 to June 2002. Primary outcome is incidence of all-cause dementia; secondary outcomes include rate of cognitive and functional decline, the incidence of cardiovascular and cerebrovascular events, and mortality. Following screening to exclude participants with incident dementia at baseline, an extensive neuropsychological assessment was performed and participants were randomly assigned to treatment groups. All participants are required to have a proxy who agreed to provide an independent assessment of the functional and cognitive abilities of the participant. Assessments are repeated every 6 months. Significant decline at any visit, defined by specific changes in cognitive screening scores, leads to a repeat detailed neuropsychological battery, neurological and medical evaluation and MRI scan of the brain. The final diagnosis of dementia is achieved by a consensus panel of experts. Side effects and adverse events are tracked by computer at the central data coordinating center and unblinded data are reviewed by an independent safety monitoring board. Studies such as these are necessary for this and a variety of other potential protective agents to evaluate their effectiveness in preventing or slowing the emergence of dementia in the elderly population.
老年痴呆症的流行、替代药物和补充剂使用的突出以及确定如何预防痴呆症的努力，促使人们开展旨在预防痴呆症的研究。银杏记忆评估（GEM）研究最初设计为一项为期5年的随机双盲、安慰剂对照试验，以每天两次、每次120毫克的剂量服用EGb761银杏叶提取物，用于预防正常老年人或轻度认知障碍者的痴呆症（尤其是阿尔茨海默病）。该研究预计对参与者进行8.5年的随访。基于目标人群（75岁以上）痴呆症发病率估计的初始功效计算得出需要进行一项3000人的研究，该研究于2000年9月至2002年6月在美国的四个临床地点成功招募。主要结局是全因痴呆症的发病率；次要结局包括认知和功能衰退率、心血管和脑血管事件的发病率以及死亡率。在筛选排除基线时患有新发痴呆症的参与者后，进行了广泛的神经心理学评估，并将参与者随机分配到治疗组。所有参与者都需要有一名代理人，该代理人同意对参与者的功能和认知能力进行独立评估。评估每6个月重复一次。在任何一次访视中，根据认知筛查分数的特定变化定义的显著衰退，会导致重复进行详细的神经心理测试、神经学和医学评估以及脑部MRI扫描。痴呆症的最终诊断由专家共识小组做出。副作用和不良事件在中央数据协调中心通过计算机进行跟踪，未盲法数据由独立的安全监测委员会进行审查。此类研究对于评估这种以及其他各种潜在保护剂在预防或减缓老年人群痴呆症出现方面的有效性是必要的。
