This systematic review of health information technology (HIT) studies found that most published studies reported positive effects on a variety of outcomes, ranging from patient safety to provider satisfaction and the effectiveness of care. This review extends and corroborates findings from a previous review published in 2006. Despite the benefits of HIT, both hospitals and clinics have been slow to implement comprehensive electronic health records, and the negative studies included in this review provide important insights into difficulties encountered while implementing HIT.