Jordan Kelvin, Dunn Kate M, Lewis Martyn, Croft Peter
Primary Care Sciences Research Centre, Keele University, Keele, Staffs ST5 5BG, United Kingdom.
J Clin Epidemiol. 2006 Jan;59(1):45-52. doi: 10.1016/j.jclinepi.2005.03.018. Epub 2005 Nov 4.
To compare methods commonly used to derive minimal important differences and recommend a rule for defining patients as clinically improved on the low back pain-specific Roland-Morris Disability Questionnaire (RMDQ).
447 primary care low back pain consulters completed a questionnaire at consultation and 6 months. Patients were classified as having achieved an important change based on methods with the best theoretical qualities, that is, the standard error of measurement, reliability change index (RCI), and modified RCI (RC(indiv)), and using a 30% reduction in score from baseline. To assess clinical importance, improvements based on these methods were compared with improvements on other back pain-related measures.
The percentage of patients rated as improved ranged from 14 to 51% by method. Using a simple rule it was possible to identify patients who had clinically important improvement (36%), patients not improved (53%), and a group of possible improvers (11%). Clinical improvement is shown if RMDQ score is reduced by 30% from baseline and back pain is rated as better on a global rating scale.
A minimal clinically important difference is derived that is clinically relevant, incorporates the measurement error of the RMDQ, and allows subjects with different grades of severity to improve.
比较常用于得出最小重要差异的方法，并推荐一种将患者定义为在腰痛特异性罗兰-莫里斯残疾问卷（RMDQ）上临床改善的规则。
447名基层医疗腰痛咨询患者在咨询时和6个月时完成了一份问卷。根据具有最佳理论质量的方法，即测量标准误差、可靠性变化指数（RCI）和改良RCI（RC(indiv)），并使用从基线得分降低30%，将患者分类为实现了重要变化。为评估临床重要性，将基于这些方法的改善与其他背痛相关测量指标的改善进行比较。
根据方法不同，被评定为改善的患者百分比在14%至51%之间。使用一个简单规则，可以识别出临床有重要改善的患者（36%）、未改善的患者（53%）以及一组可能改善的患者（11%）。如果RMDQ得分从基线降低30%且背痛在整体评定量表上被评为好转，则显示临床改善。
得出了一个最小临床重要差异，该差异具有临床相关性，纳入了RMDQ测量误差，并允许不同严重程度等级的受试者得到改善。
