The Patient-Centered Outcomes Research Institute today approved $56.7 million to study in clinical settings treatment options for appendicitis, ways to improve behavioral and mental health care, and options to prevent blood clots in patients getting hip and knee replacements. The institute also approved $9 million for two studies on obesity, one on weight loss surgery and the other on weight gain that may be caused by antibiotic use among young children. In addition, PCORI plans this fall to issue calls for proposals to provide up to $60 million for studies comparing the effectiveness of new anticoagulant drugs for blood clots and care for treatment-resistant depression.