Digital screening tool for the assessment of cognitive impairment in unsupervised setting-digiDEM-SCREEN: study protocol for a validation study. - Zeiler M; Dietzel N; Kammerer K; Frick U; Pryss R; Heuschmann P; Prokosch HU; Graessel E; Kolominsky-Rabas PL (BMJ open, 2025)