Three firms are challenging Maine and Vermont over new state laws that restrict the collection and disclosure of physician prescribing information.

IMS Health, Wolters Kluwer Health and Verispan want to prevent statutes in the two states from taking effect Jan. 1.

A similar New Hampshire law that would have limited drug company access to doctors’ prescribing habits was struck down in U.S. District Court in April on constitutional grounds.

The suits, filed today, say the Maine and Vermont statutes differ only slightly from the New Hampshire law and that they deny access to information that is central to improving the quality of care and ensuring patient safety.