An initial psychometric evaluation of the German PROMIS v1.2 Physical Function item bank in patients with a wide range of health conditions

Objectives:To translate the PROMIS Physical Function (PF) item bank version 1.2 into German and to investigate psychometric properties of resulting full bank and seven derived short forms.Design:Cross-sectional psychometric study.Setting:Inpatient and outpatient clinics of the Department of Psychosomatic Medicine at Charite–Universitatsmedizin Berlin, Germany.Subjects:A total of 10 adult patients with various chronic diseases participated in cognitive debriefing interviews. The final item bank was administered to n = 266 adult patients with a broad range of medical conditions.Interventions:Patient-reported outcome assessment as part of routine care.Main measures:PROMIS v1.2 PF bank; MOS SF-36 PF scale (PF-10).Results:Cross-cultural adaptation of the item bank followed established guidelines. For the final German translation, the corrected item-total correlations ranged from 0.44 to 0.84. Cronbach’s alpha was high for each PROMIS PF short form (α = 0.88–0.96). The full PROMIS PF bank and most short forms c...