Healthcare costs for four common procedures are rising as hospitals and health systems employ more physicians, according to a new study.

A 49% increase in hospital-employed physicians between 2012 and 2015 led to a $3.1 billion increase in Medicare costs related to four specific procedures in cardiology, orthopedics and gastroenterology, according to analysis from consulting firm Avalere Health.

Medicare paid $2.7 billion more for diagnostic cardiac catheterizations, echocardiograms, arthrocentesis and colonoscopies delivered in hospital outpatient settings than it would for treatment in independent facilities, while beneficiaries footed a $411 million higher bill.

Hospital-employed physicians performed more services in costlier hospital outpatient settings, resulting in up to 27% higher costs for Medicare and 21% for patients. For some of the procedures studied, employed physicians were seven times more likely to provide more services in a hospital outpatient setting than an independent physician’s office…