Landorf Karl B, Twyford Georgia N, Cotchett Matthew P, Whittaker Glen A
Discipline of Podiatry, School of Allied Health, Human Services and Sport, La Trobe University, Bundoora, Victoria, Australia.
Warrnambool Podiatry Group, Warrnambool, Victoria, Australia.
J Foot Ankle Res. 2024 Dec;17(4):e70021. doi: 10.1002/jfa2.70021.
The visual analogue scale (VAS) and the Foot Health Status Questionnaire (FHSQ) are patient-reported outcome measures that are frequently used to evaluate the management of plantar heel pain. This study aimed to re-calculate (i.e. revise) the minimal important differences (MIDs) of the VAS and the FHSQ when used for plantar heel pain to enhance the validity and precision of previous estimates.
This study used an anchor-based method to calculate MIDs and incorporated best-practice analyses to ensure credibility of the estimates. Data from 369 participants previously recruited from the community into four randomised controlled trials that evaluated interventions for plantar heel pain were used. VAS and FHSQ data from these participants at baseline and follow-up were pooled to calculate the MIDs (95% confidence intervals). A 15-point global rating of change Likert scale was used at follow-up as the transition scale, which was anchored to baseline. For the VAS, MIDs for two distinct types of pain were calculated: average pain and first-step pain. For the FHSQ, MIDs for two domains were calculated: foot pain and foot function.
The revised MIDs for the 100 mm VAS were -8.5 mm (95% CI: -12.2 to -4.7) for average pain and -19.2 mm (95% CI: -24.7 to -13.8) for first-step pain, which represent improvements in pain. The MIDs for the FHSQ were 12.4 points (95% CI: 6.9 to 18.0) for foot pain and 6.4 points (95% CI: 0.9 to 11.9) for foot function, which represent improvements in foot health status.
The revised MIDs from this study for the VAS and the FHSQ when used for plantar heel pain have enhanced validity and precision compared to previous estimates. This is important for clinicians and researchers as it provides a better understanding of how much improvement is required by an individual before an important change is experienced. The revised MIDs will also assist researchers with prospective sample size calculations, so future clinical trials are appropriately powered from a statistical standpoint.
视觉模拟评分法（VAS）和足部健康状况问卷（FHSQ）是患者报告的结局指标，常用于评估足底足跟痛的治疗效果。本研究旨在重新计算（即修订）VAS和FHSQ用于足底足跟痛时的最小重要差异（MID），以提高先前估计值的有效性和精确性。
本研究采用基于锚定的方法计算MID，并纳入最佳实践分析以确保估计值的可信度。使用了先前从社区招募的369名参与者的数据，这些参与者参与了四项评估足底足跟痛干预措施的随机对照试验。汇总这些参与者在基线和随访时的VAS和FHSQ数据，以计算MID（95%置信区间）。随访时使用15点全球变化评定李克特量表作为转换量表，该量表以基线为锚定。对于VAS，计算了两种不同类型疼痛的MID：平均疼痛和第一步疼痛。对于FHSQ，计算了两个领域的MID：足部疼痛和足部功能。
100mm VAS的修订后MID，平均疼痛为-8.5mm（95%CI：-12.2至-4.7），第一步疼痛为-19.2mm（95%CI：-24.7至-13.8），均表示疼痛有所改善。FHSQ的MID，足部疼痛为12.4分（95%CI：6.9至18.0），足部功能为6.4分（95%CI：0.9至11.9），均表示足部健康状况有所改善。
本研究修订后的VAS和FHSQ用于足底足跟痛时的MID与先前估计值相比，有效性和精确性均有所提高。这对临床医生和研究人员很重要，因为它能让人们更好地了解个体在经历重要变化之前需要有多大程度的改善。修订后的MID也将有助于研究人员进行前瞻性样本量计算，从而使未来的临床试验从统计学角度具有适当的效能。
