Clinical trials Below are current clinical trials.1 studies in Preventive Services Clinic (open studies only). Filter this list of studies by location, status and more. Healthcare Worker Exposure Response and Outcomes of Hydroxychloroquine Rochester, Minn. The purpose of this study is to evaluate approximately 15,000 health care workers at risk for being exposed to COVID-19. Request an Appointment at Mayo Clinic Locations, travel & lodgingCosts & insurance Feb. 21, 2020 Share on: FacebookTwitter Preventive Services ClinicSectionsOverviewRequest an appointmentTests & proceduresDoctorsLocations, travel & lodgingClinical trialsCosts & insurance Research: It's All About Patients SectionsRequest an appointmentOverviewTests & proceduresDoctorsLocations, travel & lodgingClinical trialsCosts & insurance ORG-20479134 Departments & Centers Medical Departments & Centers Preventive Services Clinic