The Pain in Dystonia Scale (PIDS)—Development and Validation in Cervical Dystonia

ABSTRACT Background A better understanding of pain in adult‐onset idiopathic dystonia (AOID) is needed to implement effective therapeutic strategies. Objective To develop a new rating instrument for pain in AOID and validate it in cervical dystonia (CD). Methods Development and validation of the Pain in Dystonia Scale (PIDS) comprised three phases. In phase 1, international experts and participants with AOID generated and evaluated the preliminary items for content validity. In phase 2, the PIDS was drafted and revised by the experts, followed by cognitive interviews to ensure self‐administration suitability. In phase 3, the PIDS psychometric properties were assessed in 85 participants with CD and retested in 40 participants. Results The final version of PIDS evaluates pain severity (by body‐part), functional impact, and external modulating factors. Test–retest reliability showed a high‐correlation coefficient for the total score (0.9, P