Anderson Jennifer J
Clinical Epidemiology Research and Training Unit, Boston University Medical Center, 715 Albany Street, Boston Mass 02118, USA.
Stat Methods Med Res. 2007 Feb;16(1):7-12. doi: 10.1177/0962280206070651.
In recent years, when reporting the results of clinical trials for chronic disease, including rheumatologic conditions, use has been made of dichotomous definitions of improvement, but it is to be expected that continuous definitions would offer improved discrimination between treatment groups. Nevertheless, a well-constructed dichotomous outcome (usually a composite) has advantages of clinical sense and specificity and may, under a variety of realistic conditions, have power that closely approximates that of standard continuous outcome measures. This has been seen for established dichotomous outcome definitions for two rheumatologic conditions, rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Simulation studies performed using multivariate normal generated data that approximates actual trial data for each of RA and AS patients demonstrate the relative power of several dichotomous and continuous outcomes in realistic situations for each of RA and AS. Although the continuous outcomes are typically more powerful than the dichotomous ones, there are some situations in which the power of a well-defined dichotomous outcome approaches or even exceeds that of a continuous outcome based on mean change.
近年来，在报告包括风湿病在内的慢性病临床试验结果时，采用了改善的二分法定义，但可以预期连续定义会在治疗组之间提供更好的区分度。然而，一个构建良好的二分结局（通常是一个综合指标）具有临床意义和特异性优势，并且在各种现实条件下，其效力可能与标准连续结局指标相近。这在类风湿关节炎（RA）和强直性脊柱炎（AS）这两种风湿病已确立的二分结局定义中得到了体现。使用多变量正态生成数据进行的模拟研究，该数据近似于RA和AS患者各自的实际试验数据，展示了在RA和AS各自的现实情况下几种二分和连续结局的相对效力。尽管连续结局通常比二分结局更有效力，但在某些情况下，一个定义明确的二分结局的效力接近甚至超过基于平均变化的连续结局的效力。
