Doctors associated with St. Joseph's Regional Medical Center are suing Horizon Blue Cross Blue Shield of New Jersey to prevent the insurer from terminating them from the Horizon network, reports The Record. In the latest round of contract negotiations, the class-action lawsuit filed by IPA of North Jersey is in response to Horizon's letters to dozens of doctors alerting them they were no longer in network. Horizon spokesman Thomas Rubino said St. Joseph's terminated the contract and chose to leave the Horizon network because it wouldn't agree to a 50 percent increase in rates. "Horizon refused such unreasonable demands, particularly in this difficult economy, since they would only work to increase premiums on our customers,'' Rubino said, adding that Horizon has offered a "reasonable'' rate increase, but St. Joseph's hasn't revoked its termination. Article