Toward a Smartphone-Based and Conversational Agent–Delivered Just-in-Time Adaptive Holistic Lifestyle Intervention for Older Adults Affected by Cognitive Decline: Two-Week Proof-of-Concept Study

Esther Brill   ^{1 *} , PhD ;   Rasita Vinay   ^{2, 3, 4 *} , PhD ;   Marcia Nißen   ^{3, 4, 5 *} , PhD ;   Priyam Joshi   ⁶ , MPH ;   Stefan Klöppel   ^{1 *} , MD ;   Tobias Kowatsch   ^{3, 4, 5 *} , PhD

¹ University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland

² Institute of Biomedical Ethics and History of Medicine, University of Zurich, Zurich, Switzerland

³ School of Medicine, University of St. Gallen, St. Gallen, Switzerland

⁴ Centre for Digital Health Interventions, Department of Management, Technology, and Economics, ETH Zurich, Zurich, Switzerland

⁵ Institute for Implementation Science in Health Care, University of Zurich, Zurich, Switzerland

⁶ Department of Psychology, Georgia State University, Atlanta, GA, United States

*these authors contributed equally