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Totten AM, Womack DM, Eden KB, et al. Telehealth: Mapping the Evidence for Patient Outcomes From Systematic Reviews [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2016 Jun. (Technical Briefs, No. 26.)

Cover of Telehealth: Mapping the Evidence for Patient Outcomes From Systematic Reviews

Telehealth: Mapping the Evidence for Patient Outcomes From Systematic Reviews [Internet].

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The purpose of this technical brief is to identify and describe the body of research evidence currently available in the form of systematic reviews to inform decisions related to contemporary practice and policy issues about telehealth. Beyond describing what is available, the brief also aims to identify key areas in which systematic reviews are insufficient for these purposes and suggest what future research (systematic reviews or primary studies) is needed.

The existence of research studies about a topic does not guarantee that the evidence is in a form that can be used to support practice and policy decisions. Ideally for research to support decisionmaking, studies need to be identified, evaluated, and synthesized into a body of evidence. Furthermore, each of these steps needs to be planned, operationalized, executed, and presented so that the evidence addresses the questions relevant to the important decisions. Decisionmakers and other stakeholders may be able to do this ad hoc if the volume of literature is small and the issues are straightforward. However, if the topic is broad and the body of literature is expansive, the task quickly becomes daunting.

This is precisely the case with telehealth. Telehealth includes several different technologies that are not treatments or inventions in and of themselves, rather the technologies are used to expand access, exchange information, and deliver care in alternate formats. Technologies such as remote patient monitoring and videoconferencing can be used to expand specialty care to seriously ill patients in intensive care units (ICUs), to patients in critical assess hospitals, or to patients and providers in areas with shortages of health care providers. Similarly, technology can be used to extend primary care to remote areas and increase the frequency of patient and primary care provider interactions. Internet applications can be used to facilitate psychiatric treatment and other counseling. Devices can be used to evaluate status in patients with chronic conditions who need close monitoring.

Many combinations of technologies, functions, and conditions have been studied to date. The National Library of Medicine added the Medical Subject Headings (MeSH) term “Telemedicine,” as a synonym for Telehealth to its list of indexing terms in 1993. As of January 2016 there were over 15,000 articles and over 400 systematic reviews that have been assigned Telemedicine as a major subject heading, indicating that telehealth is the focus of the publication.

Our task was to characterize the systematic reviews available about the effectiveness of telehealth. In this brief we present the results in the form of an evidence map. An evidence map is a combination of a systematic approach to identifying the existing literature on a topic and a description of key characteristics of the existing evidence. This description includes graphic presentation of these key characteristics. It is called a “map” because of the use of graphics and because, like a map, it is a representation that emphasizes and presents some, but not all features, just as we use topographic, economic, road, and climate maps of the same area for different purposes. An evidence map should help clarify the current state of research and possible future directions. Evidence mapping is “emerging as a less exhaustive yet systematic and replicable methodology that allows an understanding of the extent and distribution of evidence in a broad clinical area, highlighting both what is known and where gaps in evidence exist.”1 As a form of rapid review, evidence maps have been used by several organizations and are likely to become more common as the evidence base across health topics grows in size and complexity.2-11


The State of Telehealth

Telehealth encompasses multiple technologies that have been applied to health services for a wide range of conditions, populations, and settings. In fact, telehealth is one of the oldest uses of technology in health care. Telehealth interventions in place today interact with many different specialties across the continuum of care, and affect patients of all ages.12 Additionally, telehealth mirrors the rapidly changing technology environment, and the corresponding evidence base is expanding in both volume and scope. Many different definitions of telehealth are used in the scientific literature, among policy leaders, and by industry and other stakeholders. The Health Resources and Services Administration (HRSA) provides the following well-accepted definition of telehealth: “the use of telecommunications and information technologies to share information, and provide clinical care, education, public health, and administrative services at a distance.”13 There are also several related terms such as telemedicine, eHealth, and mHealth, which have been defined by the Office of the National Coordinator for Health Information Technology (ONC).14

The relationships among the many varied terms related to telehealth has been illustrated by van Dyk (Figure 1).15 The different forms of telehealth can be used in a variety of clinical areas and the technologies evaluated in the literature range from videoconferencing, image exchange, and streaming media to wireless communications and monitoring.14 These telecommunications technologies can provide long-distance health care, educate patients and providers, and support management of chronic conditions in patients' homes. The wide-ranging capabilities and applications also create one of the major challenges when systematically reviewing the literature on telehealth—the heterogeneity among existing studies. Studies of telehealth vary by setting (e.g., rural or urban; home, community, clinic, nursing home, or hospital; radiology department; pharmacy)16 by clinical indication, by health care delivery function, by type of technology, and by expected impact.

Figure 1 is a series of nested and overlapping circles to represent the varied definitions of telehealth. The largest circle is eHealth (not only over a distance), a smaller circle within the eHealth circle is telehealth (preventative, promotive and curative healthcare delivered over a distance), within the telehealth circle is telemedicine (curative). Within the telemedicine circle are telepharmacy, teleradiology, telepsychiatry, teledermatology and tele… to represent all other telemedicine possibilities. An oval that overlaps all of the circles is mHealth. A circle overlapping eHealth, telehealth, telemedicine and mHealth is telecare.

Figure 1

Scope of telehealth terminology.

Current Practice and Policy Issues

The motivation for this technical brief originates from a request by United States Senators Bill Nelson and John Thune for a literature review on the value of telehealth and remote patient monitoring, particularly for the chronically ill, with a focus on expanding access to care and reducing costs.17 A multi-stakeholder letter to Senators Bill Nelson and Susan Collins from several medical, patient advocacy, and industry groups supported the request for such a review.18 Initial searches in response to this request confirmed that there is a large volume of literature consisting of both primary studies and systematic reviews about applications of telehealth. This literature covers a broad range of topics and is of varying quality. Given both the volume and variability of the literature, it was not feasible to provide a full, comprehensive report on the evidence for effectiveness of all aspects of telehealth in a single technical brief. As such, this evidence map is the first step toward identifying domains or topics where systematic reviews have already synthesized evidence of effectiveness and topics which remain to be synthesized as well as areas where there is little primary research. As an evidence map, this technical brief was not designed to be a comprehensive review of primary research.

The request for a systematic review of “the growing body of evidence demonstrating the value of telehealth technologies”17 is rooted in a belief that telehealth has the potential to produce positive benefits, a desire to promote the effective use of telehealth, and motivation to remove barriers to its use. Telehealth has been described as having great promise in the sense that it could leverage the $30 billion investment in electronic health records that ONC has made in the last half-decade through the Health Information Technology for Economic and Clinical Health (HITECH) Act.19 While the potential benefits and possible uses have been extensively enumerated and described (e.g., improving quality, promoting safety, and expanding access),20-22 there is also a body of literature that outlines barriers and challenges to implementation and widespread adoption of telehealth.23-25 The goal of this evidence map is to increase our understanding of what uses of telehealth are supported by existing bodies of evidence in the form of systematic reviews so that resources can be used judiciously to support both systematic reviews and primary studies in areas where either research has not been conducted or the evidence is not in a usable form.

In order to inform the methodology and the structure for this evidence map we started by identifying the key issues that stakeholders hoped the research evidence would help address. We based our assessment on the letter mentioned above, our discussions with Key Informants (see Methods below for details), background materials such as reports and testimony, and our expertise derived from both an earlier review and our team's collective experience in this field.21,22,26,27

Key issues involve identifying situations where telehealth use is supported by the evidence, obtaining sustainable funding for its use, and encouraging health care providers to apply it. Although telehealth has great potential to improve health care delivery,16,28,29 challenges include problems in reimbursement, scalability, and licensure.23,24

A technical brief differs from a systematic review both in terms of scope and methodology. Because the letter from the Senators emphasized a focus on the use of telehealth within the health care system, we narrowed the scope of our analysis to interventions that included some aspect of a patient interacting with the health care system or a health care providers interacting about a specific patient for the purposes of treatment, management, or prevention of disease. These interactions could occur over distance or time, which is in real time or asynchronous and in different or the same locations. This excluded applications such as informational Web sites, mobile applications that did not facilitate interaction, and any purely educational activities. Also, because issues related to implementation are addressed after effectiveness is established, we focused on describing the available evidence related to effectiveness and did not include evaluations of telehealth implementation or spread. How these decisions were operationalized is described in the next sections on objectives and methods.

Objectives and Guiding Questions

The purpose of this technical brief is to provide a survey of the large amount of currently available research about the impact of telehealth on health outcomes and health care utilization that can be used to inform policy and practice decisions and guide future research. This differs from a common use of technical briefs to explore topics with scant evidence. This technical brief uses an evidence map format as a means of both presenting and analyzing the information. The map first focuses on describing the currently available systematic reviews that could potentially be used to guide decisions. This approach acknowledges that evidence-based decisions should be guided by a body of literature, and not usually by an individual study. The map format also provides an opportunity for two additional activities: 1) to identify areas not addressed or inadequately addressed in these reviews, for which primary literature may be robust enough for further systematic reviews, and 2) to allow enumeration of areas with gaps in evidence that will require additional primary research.

The questions below guided our work mapping the available research on telehealth interventions.

  1. What is the current research on the effectiveness of telehealth interventions?
    1. What telehealth interventions have been studied for effectiveness or harms?
      1. For which interventions are there systematic reviews available?
    2. What patient populations and conditions have been studied with telehealth interventions?
    3. What settings and situations have been studied with telehealth interventions?
    4. What primary outcomes have been studied with telehealth interventions?
    5. What study designs have been used in studies of the effectiveness of telehealth interventions?
  2. What gaps exist in the current research?
    1. Which telehealth interventions identified by experts as currently relevant have no research evidence, or inadequate evidence?
    2. For which telehealth interventions are additional primary research studies needed to answer questions important to policy and practice, e.g., additional patient populations or outcome measures?
    3. For which telehealth interventions are there sufficient primary research studies that a new systematic review would add to current knowledge?

The organizing principal for this specific evidence map, given the goals of the stakeholders, is that the evidence must be structured in terms of both format and content so that it can be used to inform current policy and practice decisions. For this reason, we include general consideration of the quality and the findings of systematic reviews in our map. Quality and results are not addressed as comprehensively as they would be in a full systematic review, and it should be noted that these topics are often not included in technical briefs. We used and adapted approaches that have been used in other literature maps to include selected elements of quality and results.5-8 We describe these approaches in the methods section of this report.


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