In addition, a growing variety of clinics (18-20%) are now run by medical facilities or doctor groups, who use or hire their own clinic and administrative staffs or use existing service provider centers to serve the worker population. Finally, an increasing variety of employers are taking part in shared, multi-employer centers, located either on one employer's place or centrally situated.The supplier will build, staff and handle the center either at the request of a group of employers or will get employers in a specified geographic area. Despite the design utilized, it's crucial that company stay participated in supplier choice, center oversight, tactical and policy direction. Staffing practices vary from one onsite center to another, though over 60% of facilities are led by a Nurse Practitioner or Physician's Assistant.