In addition, a growing variety of centers (18-20%) are now run by healthcare facilities or physician groups, who utilize or employ their own clinic and administrative personnels or use existing provider centers to serve the employee population. Finally, an increasing variety of employers are participating in shared, multi-employer clinics, situated either on one company's area or centrally situated.The vendor will build, personnel and manage the facility either at the request of a group of companies or will obtain companies in a defined geographic area. Despite the design used, it's essential that company stay participated in service provider choice, center oversight, tactical and policy instructions. Staffing practices vary from one onsite center to another, though over 60% of centers are led by a Nurse Professional or Doctor's Assistant.