Interest is emerging concerning the potential of technology and eHealth solutions that are tailored to consumers. This emerging field has been referred to as consumer health informatics (CHI). It has been defined by Eysenbach as a branch of medical informatics that "analyzes consumers' needs for information, studies and implements methods of making information accessible to consumers, and models and integrates consumers' preferences into medical information systems." For the purpose of this review, we define CHI applications as any electronic tool, technology, or system that is: 1) primarily designed to interact with health information users or consumers and 2) interacts directly with the consumer who provides personal health information to the CHI system and receives personalized health information from the tool application or system; and 3) is one in which the data, information, recommendations or other benefits provided to the consumer, may be used with a healthcare professional, but is not dependent on a healthcare professional. As such, for the purposes of this review, we have excluded point of care devices (e.g., glucometer, remote monitoring devices), prescribed clinical devices that are part of the provision of clinical care, general information websites, message boards, and applications that are designed for use in a work environment. This definition has the following advantages: 1) It keeps the focus of the review on how CHI applications meet the needs of consumers rather than the needs of clinicians; 2) It helps avoid a categorical disease-oriented evaluation of every clinical technological development for every disease which is not necessarily focused on the needs of consumers; 3) It helps to keep the focus of the review on studies that demonstrate impact, value or efficacy from the perspective of consumers; 4) It facilitates categorization of CHI applications in ways that may be more meaningful for patients. Potential categories of CHI tools/technologies/applications include but may not be limited to: a. Applications and technologies that facilitate knowing/tracking/understanding clinical parameters (disease management); b. Applications and technologies that facilitate knowing/tracking/understanding observations of daily living (ODL's); c. Applications and technologies that facilitate calendaring (lifestyle management assistance); d. Applications and technologies that facilitate prevention and health promotion; e. Applications and technologies that facilitate self-care; and f. Applications and technologies that facilitate assisted care and caregiving. The objective of the report is to review the literature on the evidence of the impact of currently developed CHI applications on health and health care process outcomes, to identify the gaps in the literature, and to recommend future research endeavors to better assess these information technology (IT) applications. The specific Key Questions were: 1. What evidence exists that CHI applications impact: a. Health care process outcomes (e.g., receiving appropriate treatment) among users? b. Intermediate health outcomes (e.g., self management, health knowledge, and health behaviors) among users? c. Relationship-centered outcomes (e.g., shared decision making or clinician-patient communication) among users? d. Clinical outcomes (including quality of life) among users? e. Economic outcomes (e.g., cost and access to care) among users? 2. What are the barriers that clinicians, developers and consumers and their families or caregivers encounter that limit utilization or implementation of CHI applications? 3. What knowledge or evidence exists to support estimates of cost, benefit, and net value with regard to CHI applications? 4. What critical information regarding the impact of CHI applications is needed in order to give consumers, their families, clinicians, and developers a clear understanding of the value proposition particular to them?