Assessment of the Systemic Sclerosis-Associated Raynaud's Phenomenon Questionnaire: Item Bank and Short-Form Development.

OBJECTIVE

To develop, refine, and score a novel patient-reported outcome instrument to assess the severity and impact of Raynaud's phenomenon (RP) in systemic sclerosis (SSc).

METHODS

The Assessment of Systemic Sclerosis-Associated Raynaud's Phenomenon (ASRAP) questionnaire items were developed with patient insight partner support and grounded in the lived patient experience of SSc-RP. ASRAP items underwent formal qualitative assessment and linguistic testing. An international multicenter study was undertaken to field test the preliminary ASRAP questionnaire.

RESULTS

A preliminary 37-item ASRAP questionnaire was supplemented with 2 additional items following expert review to enhance content coverage before undergoing formal linguistic testing to optimize readability. Patient cognitive debriefing interviews were undertaken to enhance comprehension, ambiguity, cognitive difficulty, relevance, and content coverage of both the ASRAP items and instructions. We enrolled 420 SSc patients from scleroderma centers in the UK and US over 2 consecutive winters. Factor analysis with item response theory was undertaken to remove redundant and poorly fitting items. The retained 27-item long-form ASRAP questionnaire was calibrated and scored using the graded response model. A fixed 10-item short-form ASRAP questionnaire was developed using computerized adaptive testing simulations.

CONCLUSION

The ASRAP questionnaire has been developed with extensive SSc patient input, with items grounded in the lived experience of SSc-RP to ensure strong content validity, with a focus on how patients feel and function. An advanced psychometric approach with expert input has removed redundant and/or poorly fitting items without eroding content validity. Long- and short-form ASRAP questionnaires have been calibrated and scored to permit formal validation.