Background. Telehealth includes a wide range of technologies used to fulfill many functions in in health care for patients with a variety of clinical conditions. For this evidence map, telehealth is defined as the use of information and telecommunications technology in health care delivery for a specific patient involving a provider across distance or time. Various types of telehealth interventions have been evaluated in thousands of research studies and hundreds of systematic reviews. The vast size of the literature and the variations in how the literature has been collected, evaluated, and synthesized make it challenging to determine what is known about the effectiveness of telehealth for specific purposes and what questions remain unanswered.
Purpose. The purpose of this brief is to provide an overview of the large and disparate body of evidence about telehealth for use by decisionmakers. The approach used was to create an evidence map of systematic reviews published to date that assess the impact of telehealth on clinical outcomes. This evidence map describes a limited number of key characteristics of the systematic reviews currently available in order to evaluate the bodies of evidence available to inform practice, policy, and research decisions about telehealth.
Methods. An evidence map is a specific type of rapid or abbreviated review. While the creation of the evidence map is based on systematic review methodology, its goal is to describe rather than synthesize available research and to use graphics when possible to represent selected characteristics of the evidence. We included systematic reviews that synthesized the impact of telehealth interventions on clinical outcomes, utilization, or cost. We created bubble plots to separately examine the distribution of the evidence from systematic reviews in terms of volume (number of reviews, number of patients in the included studies), conclusions about benefit by clinical focus area, and telehealth function. We also determined how much evidence is available about combinations of clinical areas and telehealth functions reported in existing systematic reviews. We supplemented this by summarizing the topics covered in excluded reviews and the results of exploratory searches for primary studies on selected topics in order to assess the need for future systematic reviews or primary studies in key telehealth domains.
Findings. We identified 1,494 citations about telehealth, from which 58 systematic reviews met our inclusion criteria. A large volume of research reported that telehealth interventions produce positive outcomes when used for remote patient monitoring, broadly defined, for several chronic conditions and for psychotherapy as part of behavioral health. The most consistent benefit has been reported when telehealth is used for communication and counseling or remote monitoring in chronic conditions such as cardiovascular and respiratory disease, with improvements in outcomes such as mortality, quality of life, and reductions in hospital admissions. Given sufficient evidence of effectiveness for these topics, the focus of future research should shift to implementation and practice-based research. Topics with an evidence base that could be the focus of future systematic reviews include telehealth for consultation, uses in intensive care units, and applications in maternal and child health. We also identified topics with a limited