Retail clinics, which seemed to be growing exponentially not long ago, have slowed in their openings, but another branch of this industry has taken off.  Very nearly a third of companies employing more than a thousand workers have installed on-site clinics or plan to this year.  Toyota, Nissan, Harrah’s, and Walt Disney are among those companies.  One study showed that on-site clinics reduced workers visits to hospital Emergency Departments by 72%.     MORE