Psychometric validation of the Hand Disability in Systemic Sclerosis-Digital Ulcers (HDISS-DU®) patient-reported outcome instrument.

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®).