The Julius Center coordinates and participates in several large research cohorts. These cohorts are an important base for research and provide ample opportunities for obtaining financial research support. Moreover, the projects of the GP-network Utrecht and the Utrecht Health Project are intended to create an infrastructure in which research questions on efficacy and effectiveness of health care and effects of (local) health care policy can be answered. The latter is of major importance for increasing the expertise in the areas of health care improvement, extramural health care and general practice.

The major cohorts are:
• ADDITION
• AGIS Health database
• ARYA
• DOM
• Electronic patient records communication disorders
• EPIC-NL
• HNU
• IJSCO
• Julius Primary Care Network (Julius Huisartsen Netwerk, JHN)
• Netherlands Amniotic Fluid (NAF) cohort
• PCR-MN
• PIAMA
• PREDICT
• PROSPECT-EPIC
• PROVIDI
• SMART
• Utrecht Health Project (LRGP)
• Whistler