What is the relationship between the minimally important difference and health state utility values? The case of the SF-6D.
What is the relationship between the minimally important difference and health state utility values? The case of the SF-6D.
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DOI：
10.1186/1477-7525-1-4
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发表时间：
2003-04-11
影响因子：
3.6
通讯作者：
Brazier, John E
中科院分区：
文献类型：
--
作者：
Walters, Stephen J;Brazier, John E
背景：SF-6D是从SF-36派生的一种新的基于偏好的单一汇总健康测量工具。需要进行实证研究，以确定SF-6D得分的最小变化是什么，对卫生专业人员、患者和其他利益相关者来说是重要的和有意义的。目的：使用基于锚点的方法来确定各种数据集的SF-6D的最小重要差异(MID)。方法：只要SF-6D中使用的11个条目都已完成，原始SF-36问卷的所有应答者都可以被分配一个SF-6D得分。SF-6D可以被认为是一个连续的结果，在0.29到1.00的范围内得分，1.00代表“完全健康”。基于锚点的方法研究与健康相关的生活质量(HRQOL)测量和独立测量(或锚点)之间的关系，以阐明特定程度变化的含义。一种基于锚点的方法使用MID的估计，即QOL量表中的差异对应于自我报告的全球范围内微小但重要的变化。对患者进行一段时间的跟踪，然后使用SF-36的问题2作为我们的全球评级量表(这不是SF-6D的一部分)，询问与上次评估相比，总体健康状况是否比上次评估要好得多(5)、略好(4)、保持不变(3)、略差(2)或更差(1)。我们认为总体评分为4或2的患者经历了与MID相同的变化。在报告健康状况恶化(全球变化1或2)的患者中，SF-6D得分变化的符号相反(即乘以负1)。结果：本文描述了7项既往使用SF-36的纵向研究的SF-6D的MID。结论：在7项回顾研究(9个患者组)中，SF-6D的MID范围为0.010~0.048，加权平均估计为0.033(95%CI：0.029~0.037)。相应的标准化反应平均数(SRM)在0.11至0.48之间，平均值为0.30，根据Cohen的标准，主要在“小到中等”的范围内，支持中等结果。使用半标准差(变化)方法，平均效应大小为0.051(范围为0.033至0.066)。需要进一步的经验性研究，以确定这是否适用于其他患者群体和人群。
BACKGROUND: The SF-6D is a new single summary preference-based measure of health derived from the SF-36. Empirical work is required to determine what is the smallest change in SF-6D scores that can be regarded as important and meaningful for health professionals, patients and other stakeholders.OBJECTIVES: To use anchor-based methods to determine the minimally important difference (MID) for the SF-6D for various datasets.METHODS: All responders to the original SF-36 questionnaire can be assigned an SF-6D score provided the 11 items used in the SF-6D have been completed. The SF-6D can be regarded as a continuous outcome scored on a 0.29 to 1.00 scale, with 1.00 indicating "full health". Anchor-based methods examine the relationship between an health-related quality of life (HRQoL) measure and an independent measure (or anchor) to elucidate the meaning of a particular degree of change. One anchor-based approach uses an estimate of the MID, the difference in the QoL scale corresponding to a self-reported small but important change on a global scale. Patients were followed for a period of time, then asked, using question 2 of the SF-36 as our global rating scale, (which is not part of the SF-6D), if there general health is much better (5), somewhat better (4), stayed the same (3), somewhat worse (2) or much worse (1) compared to the last time they were assessed. We considered patients whose global rating score was 4 or 2 as having experienced some change equivalent to the MID. In patients who reported a worsening of health (global change of 1 or 2) the sign of the change in the SF-6D score was reversed (i.e. multiplied by minus one). The MID was then taken as the mean change on the SF-6D scale of the patients who scored (2 or 4).RESULTS: This paper describes the MID for the SF-6D from seven longitudinal studies that had previously used the SF-36.CONCLUSIONS: From the seven reviewed studies (with nine patient groups) the MID for the SF-6D ranged from 0.010 to 0.048, with a weighted mean estimate of 0.033 (95% CI: 0.029 to 0.037). The corresponding Standardised Response Means (SRMs) ranged from 0.11 to 0.48, with a mean of 0.30 and were mainly in the "small to moderate" range using Cohen's criteria, supporting the MID results. Using the half-standard deviation (of change) approach the mean effect size was 0.051 (range 0.033 to 0.066). Further empirical work is required to see whether or not this holds true for other patient groups and populations.