Dr. Timothy Hahn's fellowship research focused on comparing the outcomes of relapsed juvenile ideopathic arthritis patients treated with either intraarticular steroid injection or a return to disease-modifying antirheumatic drug therapies. He employed the CARRA database for the project and developed significant expertise in the vetting and statistical manipulation of voluminous data. He also has a significant expertise and research interest in the use of ultrasonography to help manage juvenile ideopathic arthritis patients.

Dr. Timothy Hahn serves as a research mentor for fellows in the Pediatric Rheumatology Fellowship at Penn State Children's Hospital. Fellows choosing Dr. Hahn for their research mentor have the benefit of his database, statistical and ultrasound expertise.