His research focuses on evidence-based medicine for older patients with the aim to improve the quality of healthcare for older patients. In 2011, Dr. Mooijaart founded the national Institute for Evidence-based Medicine in Old Age | IEMO (www.iemo.nl), a collaboration of Dutch University Medical Centers, other knowledge institutions and industry. In 2012, Dr. Mooijaart initiated the Acutely Presenting Older Patient study (www.apop.eu), a prospectively collected cohort of over 2,700 older patients visiting the emergency department to identify patients at highest risk of poor outcomes and target interventions to improve outcomes.