Interpretation of changes in health-related quality of life - The remarkable universality of half a standard deviation
Interpretation of changes in health-related quality of life - The remarkable universality of half a standard deviation
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DOI：
10.1097/00005650-200305000-00004
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发表时间：
2003-05-01
期刊：
影响因子：
3
通讯作者：
Wyrwich, KW
中科院分区：
文献类型：
--
作者：
Norman, GR;Sloan, JA;Wyrwich, KW
背景。许多研究计算了与健康相关的生活质量仪器的最小重要差异（MID）。确定不同仪器估计的MID值的大小是否一致。我们对文献进行了系统回顾，以确定计算MID的研究，并包含足够的信息来计算效应量（ES）。38项研究符合标准，结果为62项。除6项研究外，其余研究的MID估计接近0.5个标准差（平均值= 0.495，标准差= 0.155）。与疾病特异性或通用仪器或反应选项的数量等因素没有一致的关系。负变化与较大的ESs无关。基于人群的估计程序和简短随访与较小的ESs和较大ESs的急性疾病相关。对这种一致性的一种解释是，心理学研究表明，人们在广泛的任务范围内区分能力的极限大约是七分之一，这非常接近sd的一半。在大多数情况下，慢性病与健康相关的生活质量变化的歧视阈值似乎约为标准差的一半。
BACKGROUND. A number of studies have computed the minimally important difference (MID) for health-related quality of life instruments.OBJECTIVE. To determine whether there is consistency in the magnitude of MID estimates from different instruments.METHODS. We conducted a systematic review of the literature to identify studies that computed an MID and contained sufficient information to compute an effect size (ES). Thirty-eight studies fulfilled the criteria, resulting in 62 ESs.RESULTS. For all but 6 studies, the MID estimates were close to one half a SD (mean = 0.495, SD = 0.155). There was no consistent relationship with factors such as disease-specific or generic instrument or the number of response options. Negative changes were not associated with larger ESs. Population-based estimation procedures and brief follow-up were associated with smaller ESs, and acute conditions with larger ESs. An explanation for this consistency is that research in psychology has shown that the limit of people's ability to discriminate over a wide range of tasks is approximately 1 part in 7, which is very close to half a SD.CONCLUSION. In most circumstances, the threshold of discrimination for changes in health-related quality of life for chronic diseases appears to be approximately half a SD.