BACKGROUND We aimed to develop a patient-reported outcome measure, in accordance with the US Food and Drug Administration guidance, to capture the impact of systemic sclerosis-related digital ulcers (SSc-DUs) on hand function. Psychometric analyses were conducted to evaluate and document the measurement properties of the resulting instrument-the Hand Disability in Systemic Sclerosis-Digital Ulcers (HDISS-DU®). METHODS The HDISS-DU was developed through a series of confirmatory, qualitative concept-elicitation interviews (N = 36) to provide supportive evidence that the instrument captures all relevant issues and functional limitations relating to SSc-DUs in this patient population. Psychometric analyses used blinded data from two randomised, controlled, phase 3 trials in patients with SSc-DUs (N = 517). The analyses included assessment of reliability, construct validity, responsiveness and thresholds for meaningful change. RESULTS Qualitative interviews confirmed that the HDISS-DU had good content coverage and patients understood the HDISS-DU instructions, items and response scale. The HDISS-DU demonstrated excellent internal consistency and test-retest reliability, with satisfactory construct validity. Overall, the HDISS-DU was highly responsive to change in digital ulcer severity: the no-change group (for other criterion measures) had mean differences and effect sizes close to 0, while mean differences were mostly negative (indicating improvement) for the improvement groups (for other criterion measures) and vice versa. The preliminary threshold for meaningful change was a 0.50 difference in HDISS-DU score. CONCLUSIONS Using data from two large studies of SSc-DU patients, these psychometric analyses support the reliability, validity, discriminating ability and responsiveness to change of the HDISS-DU for evaluating treatment outcomes in future clinical studies and clinical practice.

中文翻译：

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患者报告的结局仪器的系统性硬化性数字溃疡（HDISS-DU®）手部残疾的心理计量学验证。

背景技术我们的目标是根据美国食品和药物管理局的指导，开发一种患者报告的结局指标，以捕获全身性硬化相关数字溃疡（SSc-DUs）对手部功能的影响。进行了心理测量分析，以评估和记录所得仪器的测量特性-系统性硬化症中的手部残疾-数字溃疡（HDISS-DU®）。方法HDISS-DU是通过一系列确认性，定性概念启发访谈（N = 36）开发的，目的是提供支持性证据，证明该仪器可捕获该患者人群中与SSc-DUs相关的所有相关问题和功能限制。心理测量分析使用了来自SSc-DUs（N = 517）患者的两项随机对照3期试验的盲数据。分析包括可靠性，结构效度，响应能力和有意义的变化的阈值的评估。结果定性访谈证实HDISS-DU具有良好的内容覆盖率，患者了解了HDISS-DU的使用说明，项目和反应量表。HDISS-DU具有出色的内部一致性和重测可靠性，并具有令人满意的构建有效性。总体而言，HDISS-DU对数字溃疡严重程度的变化具有高度的响应：无变化组（用于其他标准措施）的平均差异和效应量接近于0，而平均差异大部分为改善的负值（表明有所改善）组（用于其他标准量度），反之亦然。有意义的改变的初步阈值是HDISS-DU得分相差0.50。