Validation of MAP Personal non-commercial use only. The Journal of Rheumatology United States

Abstract

ABSTRACT. Objective. To evaluate some measurement properties of the Myositis Activities Profile (MAP) in adult patients with polymyositis (PM) and dermatomyositis (DM) in the United States. Methods. To assess content validity, patients with PM/DM rated difficulty and importance of items of the MAP using a visual analog scale (VAS), range 0-10. For construct validity, consecutive patients with PM/DM performed the 6-item core set for disease activity including the manual muscle test (MMT) and the Health Assessment Questionnaire (HAQ), the Functional Index-2 (FI-2; muscle endurance), and the MAP plus disease effect on well-being on a VAS. Item fit within subscales was analyzed by Cronbach's alpha. Patients with stable disease activity filled out the MAP again 1 week later