Kymes Steven M, Lee Kelvin, Fletcher James W
Washington University School of Medicine, Department of Ophthalmology and Visual Sciences, St Louis, MO, USA.
Clin Trials. 2006;3(1):31-42. doi: 10.1191/1740774506cn131oa.
Diagnostic tests, particularly diagnostic imaging modalities such as computed tomography (CT) and positron emission tomography (PET), have the potential to make important contributions to improved patient care and medical decision making. The expense of these tests is justified to the extent that they improve diagnostic and treatment decisions, and ultimately health outcomes. Clinical studies evaluating the accuracy of diagnostic tests and assessing their influence on decision making are essential to setting health policy and directing patient care.
We present the design and participant baseline characteristics of the Department of Veterans Affairs Cooperative Study 027 (Prospective Study of the Diagnostic Accuracy of 18F-Fluorodeoxyglucose (FDG) - Positron Emission Tomography (PET) Imaging in the Management of Patients with Solitary Pulmonary Nodules (SNAP).
SNAP is a prospective, multi-site diagnostic trial to evaluate the efficacy of PET and CT for characterizing solitary pulmonary nodules. The study incorporated an assessment of the impact of these imaging modalities on clinical decision making.
Between January 1999 and June 2001, 10 SNAP sites enrolled 532 participants with a mean age of 66 years (SD +/- 11.3), of whom 97.3% were male. A history of smoking was claimed by 93.6% of participants, with 45.7% of all participants smoking at time of enrollment. Those still smoking had an average exposure of 56.8 pack-years, while those who had quit smoking prior to enrollment had an exposure of 58.1 pack-years.
The study design reduced most common biases, but some degree of selection bias and verification bias remained. We sought to minimize verification bias by use of a dual reference standard.
SNAP is a diagnostic test study that was designed to minimize bias and to assess a test's impact on clinical decision making, providing the kind of information most needed by clinicians and health policy makers.
诊断测试，尤其是诸如计算机断层扫描（CT）和正电子发射断层扫描（PET）等诊断成像方式，有潜力为改善患者护理和医疗决策做出重要贡献。只要这些测试能改善诊断和治疗决策并最终改善健康结果，其费用就是合理的。评估诊断测试准确性并评估其对决策影响的临床研究对于制定卫生政策和指导患者护理至关重要。
我们介绍了退伍军人事务部合作研究027（18F-氟脱氧葡萄糖（FDG）-正电子发射断层扫描（PET）成像在孤立性肺结节患者管理中的诊断准确性前瞻性研究）的设计和参与者基线特征。
SNAP是一项前瞻性、多中心诊断试验，旨在评估PET和CT对孤立性肺结节特征的评估效果。该研究纳入了对这些成像方式对临床决策影响的评估。
在1999年1月至2001年6月期间，10个SNAP研究点招募了532名参与者，平均年龄为66岁（标准差±11.3），其中97.3%为男性。93.6%的参与者有吸烟史，所有参与者中有45.7%在入组时仍在吸烟。仍在吸烟的参与者平均吸烟量为56.8包年，而在入组前戒烟的参与者吸烟量为58.1包年。
该研究设计减少了大多数常见偏差，但仍存在一定程度的选择偏差和验证偏差。我们试图通过使用双重参考标准来尽量减少验证偏差。
SNAP是一项诊断测试研究，旨在尽量减少偏差并评估测试对临床决策的影响，提供临床医生和卫生政策制定者最需要的那种信息。
