Objective Clinical trialists, meta-analysts and clinical guideline developers are increasingly using minimal important differences (MIDs) to enhance the interpretability of patient-reported outcome measures (PROMs). Here, we elucidate three critical issues of which MID users should be aware. Improved understanding of MID concepts and awareness of common pitfalls in methodology and reporting will better inform the application of MIDs in clinical research and decision-making. Methods We conducted a systematic review to inform the development of an inventory of anchor-based MID estimates for PROMs. We searched four electronic databases to identify primary studies empirically calculating an anchor-based MID estimate for any PROM in adolescent or adult populations across all clinical areas. Our findings are based on information from 338 studies reporting 3389 MIDs for 358 PROMs published between 1989 and 2015. Results We identified three key issues in the MID literature that demand attention. (1) The profusion of terms representing the MID concept adds unnecessary complexity to users’ task in identifying relevant MIDs, requiring meticulous inspection of methodology to ensure estimates offered truly reflect the MID. (2) A multitude of diverse methods for MID estimation that will yield different estimates exist, and whether there are superior options remains unresolved. (3) There are serious issues of incomplete presentation and reporting of key aspects of the design, methodology and results of studies providing anchor-based MIDs, which threatens the optimal use of these estimates for interpretation of intervention effects on PROMs. Conclusions Although the MID represents a powerful tool for enhancing the interpretability of PROMs, realising its full value will require improved understanding and reporting of its measurement fundamentals. All data relevant to the study are included in the article or uploaded as supplementary information.

中文翻译：

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注意确定最小重要差异的方法：需要考虑的三个关键问题

目的 临床试验人员、荟萃分析人员和临床指南制定者越来越多地使用最小重要差异 (MID) 来增强患者报告结果测量 (PROM) 的可解释性。在这里，我们阐明了 MID 用户应该注意的三个关键问题。提高对 MID 概念的理解以及对方法和报告中常见陷阱的认识将更好地为 MID 在临床研究和决策中的应用提供信息。方法 我们进行了系统回顾，为 PROM 的基于锚定的 MID 估计清单的开发提供信息。我们检索了四个电子数据库来确定主要研究，这些研究根据经验计算了所有临床领域青少年或成人人群中任何 PROM 的基于锚定的 MID 估计值。我们的研究结果基于 1989 年至 2015 年间发表的 338 项研究的信息，这些研究报告了 358 个 PROM 的 3389 个 MID。 结果 我们确定了 MID 文献中需要注意的三个关键问题。(1) 代表 MID 概念的大量术语给用户识别相关 MID 的任务增加了不必要的复杂性，需要对方法进行仔细检查以确保提供的估算真实反映 MID。(2) 存在多种不同的 MID 估计方法，这些方法会产生不同的估计值，并且是否存在更好的选择仍然悬而未决。(3) 提供锚定 MID 的研究的设计、方法和结果的关键方面存在不完整的表述和报告的严重问题，这威胁到这些估计值在解释 PROM 干预效果时的最佳使用。结论 尽管 MID 是增强 PROM 可解释性的强大工具，但要实现其全部价值，需要更好地理解和报告其测量基础知识。与研究相关的所有数据都包含在文章中或作为补充信息上传。