Information technology (IT) is playing a key role in health care improvement. IT artifacts enable better reach and access to health, allowing patients to manage care more effectively. Amongst various IT artifacts, a health infomediary is an online health platform that connects patients and providers with the purpose of sharing experience and knowledge for health management. Health infomediary has a potential to facilitate patient empowerment, which is an important concept leading to a better health. A number of health infomediaries have emerged with the attempt to share health knowledge and to increase patient's access to care delivery. However, how these infomediaries are useful in patient empowerment remains a research gap to be addressed. This dissertation focuses on this phenomenon and is comprised of two essays that delve into the issue of patient empowerment using infomediaries. The first essay explores the effect of doctor rating systems on willingness to take health-related action in the context of health infomediary specialized in medical tourism. The study is extended to investigate the effect of trust in infomediary and information quality on willingness to travel abroad for treatment, as well as how doctor rating systems moderate these relationships. The second essay investigates the effect of self-concept and emotional empowerment on knowledge sharing behavior in a health infomediary specialized in reconstructive surgery. The combination of these two essays sets the foundation for the argument that health infomediary is an IT tool that can facilitates patient empowerment through different mechanisms. These two studies have the potential to contribute to the existing literature in exploring how health IT can positively impact healthcare, and how particular health IT features and attributes enhance the efficiency of healthcare delivery. Additionally, we highlight managerial implications to support the development and design of health IT with the goal of providing more efficient and sustainable healthcare delivery and services. This dissertation also includes research and practical implications that are paramount to the formulation of the strategies to enhance the design of health IT artifacts, which can potentially increase the overall effectiveness of healthcare delivery. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]