Newt Gingrich’s Washington-based advocacy on behalf of a broad array of health care interests has been far more extensive than the Republican presidential candidate has acknowledged, a review by the Center for Public Integrity has found.

Since 2003, the former House speaker’s Center for Health Transformation has taken an active role in circulating policy papers, testifying at congressional hearings and using other forums to build support for dozens of pieces of legislation and federal policy initiatives that would financially benefit clients who paid as much as $200,000 a year for his services, records show.