Jaeschke R, Guyatt G H, Keller J, Singer J
Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada.
Control Clin Trials. 1991 Aug;12(4 Suppl):226S-233S. doi: 10.1016/s0197-2456(05)80026-1.
To provide additional evidence regarding the plausible range of the differences in health-related quality of life (HRQL) questionnaire scores within which the minimal important difference (MID) falls, we reviewed the results of 32 randomized controlled trials in individual subjects (N of 1 RCTs) with chronic diseases. These trials had been conducted to establish whether a patient was obtaining more good than harm from a medication. Each N of 1 RCT included a series of pairs of treatment periods, one period on active drug, and one on placebo or alternative drug. We examined the relationship between small (MID), medium, and large differences between periods within pairs, as indicated by Global Ratings and differences between these same periods according to HRQL questionnaires. The results showed a mean difference of 0.29 points per question in HRQL questionnaire scores corresponded to the MID. Differences of approximately 0.66 points per question corresponded to a moderate difference as ranked by the Global Rating; difference of about 1.09 points per question represented marked difference.
为了提供更多证据，以确定健康相关生活质量（HRQL）问卷分数差异的合理范围，即最小重要差异（MID）所在的范围，我们回顾了32项针对患有慢性病的个体受试者的随机对照试验（1项随机对照试验的样本量）的结果。这些试验旨在确定患者从药物治疗中获得的益处是否大于危害。每项1项随机对照试验都包括一系列成对的治疗期，一个治疗期使用活性药物，另一个治疗期使用安慰剂或替代药物。我们根据总体评分以及HRQL问卷中相同治疗期之间的差异，研究了成对治疗期内小（MID）、中、大差异之间的关系。结果显示，HRQL问卷分数中每个问题的平均差异为0.29分对应于MID。每个问题约0.66分的差异对应于总体评分所界定的中等差异；每个问题约1.09分的差异代表显著差异。
