Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.
J Clin Epidemiol. 2013 Aug;66(8):847-55. doi: 10.1016/j.jclinepi.2013.03.009. Epub 2013 Jun 6.
To investigate whether it is valid to combine follow-up and change data when conducting meta-analyses of continuous outcomes.
Meta-epidemiological study of randomized controlled trials in patients with osteoarthritis of the knee/hip, which assessed patient-reported pain. We calculated standardized mean differences (SMDs) based on follow-up and change data, and pooled within-trial differences in SMDs. We also derived pooled SMDs indicating the largest treatment effect within a trial (optimistic selection of SMDs) and derived pooled SMDs from the estimate indicating the smallest treatment effect within a trial (pessimistic selection of SMDs).
A total of 21 meta-analyses with 189 trials with 292 randomized comparisons in 41,256 patients were included. On average, SMDs were 0.04 standard deviation units more beneficial when follow-up values were used (difference in SMDs: -0.04; 95% confidence interval: -0.13, 0.06; P=0.44). In 13 meta-analyses (62%), there was a relevant difference in clinical and/or significance level between optimistic and pessimistic pooled SMDs.
On average, there is no relevant difference between follow-up and change data SMDs, and combining these estimates in meta-analysis is generally valid. Decision on which type of data to use when both follow-up and change data are available should be prespecified in the meta-analysis protocol.
探究在对连续结局进行荟萃分析时，合并随访数据和变化数据是否有效。
对膝关节/髋关节骨关节炎患者的随机对照试验进行了荟萃分析，该研究评估了患者报告的疼痛。我们根据随访和变化数据计算了标准化均数差值（SMD），并对SMD 的组内差异进行了合并。我们还得出了表明试验内最大治疗效果的合并 SMD（SMD 的乐观选择），并从表明试验内最小治疗效果的估计中得出了合并 SMD（SMD 的悲观选择）。
共纳入了 21 项荟萃分析，其中包含 189 项试验，涉及 41256 名患者的 292 项随机对照比较。平均而言，当使用随访值时，SMD 更有益 0.04 个标准差单位（SMD 差值：-0.04；95%置信区间：-0.13，0.06；P=0.44）。在 13 项荟萃分析（62%）中，乐观和悲观合并 SMD 之间存在相关的临床和/或显著性差异。
平均而言，随访数据和变化数据 SMD 之间没有显著差异，在荟萃分析中合并这些估计值通常是有效的。当有随访和变化数据时，应在荟萃分析方案中预先指定使用哪种类型的数据。
