The Center for Disease Control (CDC) estimates that over 18 million adults in the USA have a diagnosis of asthma—incurring over 14 million physician office visits, more than 1 million emergency room (ER) visits, and billions of dollars in health-care costs [5]. Standard treatment strategies are aimed at reducing exacerbations, improving patient functional status, and preventing death [5, 6]. Management challenges encompass medication nonadherence and poor patient recognition of symptoms leading to delays in seeking medical care [7]. The goal of telemedicine is to improve patient education concerning their disease pathology, increase medication adherence, and prevent unnecessary hospitalizations, ER visits, and absenteeism of work/school [6, 7]. A 2009 non-blinded randomized study conducted in the Netherlands by van der Meer et al. utilized an Internet-based self-management (IBSM) model in addition to usual care and compared results to usual care alone [8]. Study participants included 200 patients with a diagnosis of asthma, age 18–50 years old, with at least a 3-month prescription of inhaled corticosteroids. The IBSM comprised a web-based profile in which patients reported symptoms electronically on a daily basis and completed an Asthma Control Questionnaire (ACQ) that was submitted weekly via their personal password-protected page. The Internet group received instant weekly feedback based on their ACQ for step-up or step-down treatment strategies. After a 12-month monitoring period, this study showed a significant improvement of quality of life , symptom-free days, lung function, and overall asthma control in the Internet group as compared to usual care [8] .

In 2011, Mclean et al. performed a Cochrane review of 21 randomized control trials (RCTs) that evaluated telehealth management strategies of asthma. Interventions included provider phone calls, text messages, video conferencing, or other Internet monitoring. The studies evaluated various endpoints including quality of life , ER visits, hospital admissions, medication administration technique, peak flow recordings, and symptoms. They found no significant difference in quality of life or ER visits. However, there was a statistically significant reduction in hospital admissions in patients that received telehealth services evidenced by a relative risk ratio of 0.25 [9]. The authors do acknowledge that in many of the studies, patients that were randomized to control arms received “enhanced face-to-face care,” as opposed to standard care, which could diminish the apparent effect of the intervention [9] .

Morrison et al. performed a systematic review in 2014 of articles that explored telemedicine in asthma management via interventions through the use of tablets/smartphones, computers, or a “purpose built electronic device,” as compared to usual care [6]. Of the studies included, usual care ranged from no intervention to enhanced care with multiple face-to-face teaching sessions and in some cases intermittent use of the intervention [6]. They evaluated ten review articles, including 19 unique RCTs, which included children and adults less than age 65. Primary outcomes in these studies included quality of life , activity limitations, lung function, medication use, and symptoms [6]. They determined that telemedicine techniques might be useful in improving medication compliance, patient knowledge and awareness, quality of life, and function. However, many of the studies used enhanced usual care as previously mentioned, which could confound the gravity of the effect of telehealth interventions in these studies. The authors also noted that exact mechanisms of technology use were vague and many studies did not discuss cost-effectiveness, patient accessibility, or socioeconomic status. Recognizing the limitations of the available data, telemedicine interventions certainly show promise in the chronic management of asthma; however, more studies are needed to determine its true impact and cost-effectiveness [6] .

COPD is defined by the American Thoracic Society as “a preventable and treatable disease state characterized by airflow limitation that is not fully reversible [10].” In 2010, the National Heart, Lung, and Blood Institute (as cited in CHEST) projected that COPD would incur approximately $29.5 billion in direct health-care costs in the USA annually, generating a substantial financial burden on the American population [11]. A hallmark of the disease course in patients with COPD is exacerbation of symptoms leading to decompensation requiring ER evaluation and treatment, medical or intensive care admission for management, and a resultant negative impact on the patient’s quality of life [11, 12]. There have been several studies and initiatives which incorporate telehealth monitoring for COPD patients. McLean et al. reviewed ten randomized control clinical trials that implemented telehealth strategies for COPD management in 2011. Primary endpoints evaluated over a 12-month period included number of ER visits, quality of life (measured by the St. George’s Respiratory Questionnaire [13]), number of COPD exacerbations, and death [14]. This review concluded that the use of telemedicine is associated with a significant reduction in ER visits (odds ratio 0.27), hospital admissions (odds ratio 0.46), and improvement in quality of life [14]. There was no statistical difference in mortality rates among groups .

In contrast, a randomized, multicenter, researcher-blinded study conducted by Pinnock et al. in 2013 reported no difference in outcomes with telemedicine management, including the number of exacerbations, quality of life, or hospital admissions [15]. This UK-based study included 256 patients diagnosed with COPD, with 128 patients randomized to telemedicine or standard care. Patients within the intervention arm had a home telemonitoring system installed with instructions on recording symptoms and pulse oximetry. A remote team would monitor electronically and provide treatment advice based on a standardized algorithm. After a year of monitoring and data collection, they concluded there was no significant clinical difference in telemedicine monitoring and usual care for chronic COPD management [15] .

In 2014, Tabak et al. conducted a randomized pilot study that implemented a telehealth program based on four points of monitoring which included web-based exercise programs, an electronic activity monitor and smartphone for activity goals, online self-management modules instructing patients on how to treat exacerbations, and web-based teleconsultation options providing a venue for patients to ask questions of a physiotherapist [12]. Interventions were centered on improving physical activity and modifying behaviors. Out of 29 patients, 15 were randomized to the intervention group and 14 patients to usual care. While no clinical differences were demonstrated, the study was limited by a small sample size and high dropout rate of the control group. Despite this, there was a reported increase in patient satisfaction in the telehealth group.

Currently, the data on telehealth strategies in COPD management are largely inconclusive [12, 15, 16]. Many studies had small sample sizes, short duration of follow-up, and lack of standardization of telehealth methods resulting in insufficient evidence to support clinical use of telemedicine in COPD management [16]. Further research with larger RCTs is necessary before telehealth can be instituted into standard clinical practice for COPD long-term management .

Diabetes is a chronic disease that affects billions worldwide. The CDC estimates that approximately 29 million Americans have diabetes, of which about 8 million are undiagnosed [17]. Those affected experience significantly increased morbidity and mortality due to effects on multiple organ systems. In addition, diabetes contributes to substantial financial costs totaling over $200 billion in the USA alone [17–19]. Several studies support telemedicine management in diabetes evidenced by improved glycemic control demonstrated through a reduction in hemoglobin A1c (Hgb A1c) .

Marcolino et al. performed a meta-analysis of 15 studies in 2013 aimed at determining the effectiveness of telehealth management in addition to usual care in type 1 and type 2 diabetics. Interventions ranged from nursing phone calls to full home telemonitoring devices that could transmit blood glucose values and blood pressure measurements to medical personnel [19]. They found a significant reduction in Hgb A1c, with a greater reduction in the first 6 months as compared to the 1-year follow-up. Secondary points included low-density lipoprotein (LDL) and blood pressure monitoring; however, no significant reduction was noted in these outcomes. A greater reduction of Hgb A1c was noted in the subgroup analysis for type 1 diabetics, which could be associated with age, as these patients tended to be younger and more technologically savvy, as opposed to the type 2 population [19].

In a meta-analysis by Zhai et al. in 2014, a statistically significant reduction in Hgb A1c was demonstrated among type 2 diabetic patients in the telemedicine intervention groups. They analyzed 35 RCTs, 19 of which employed an Internet-based module for telemonitoring. The remaining studies used telephone-based interventions [20]. The absolute reduction in Hgb A1c was actually reported to be small. Moreover, a slightly higher absolute reduction of A1c was noted in the studies that used telephone-based models (calls or text messages) in addition to usual care, as opposed to the use of Internet-based modules. The mean age of study participants in the trials included ranged from 42.5 to 70.8 years in the intervention groups and 42.3–70.9 years in the control group [20]. It is not clear why there was a difference between telephone and Internet-based modules; however, age could be a factor given that type 2 diabetic patients are typically older and more likely to be familiar with telephone-based communication compared to web-based methods .

Cassimatis et al. conducted a meta-analysis that reviewed the effect of telehealth interventions not only in terms of glycemic control but also examined dietary adherence, physical activity, and medication compliance in patients with type 2 diabetes [21]. Telehealth interventions utilized in the studies consisted of scheduled telephone calls from trained staff in addition to diabetes education, and one study also used periodic cell phone video messages on diabetes self-care topics. Glycemic control, physical activity, and dietary compliance were significantly improved in the telehealth groups [21] .

Overall, current data suggest that implementation of telemedicine strategies in patients with type 1 and type 2 diabetes improves glycemic control, physical activity, and adherence to dietary restrictions [19–21]. However, although many studies report a statistically significant reduction in A1c, the actual reduction was less than 1 % in many of the studies reviewed; thus, the clinical relevance of these interventions has yet to be determined and warrants further investigation [21]. Cost-effectiveness was rarely addressed in these studies, and thus the data available are not widely applicable to draw a definitive conclusion in terms of overall economic effect .

The American Heart Association reports that approximately half of all patients with HF will die within 5 years of diagnosis [22]. As a result, significant research efforts have been dedicated to the optimization of its management, producing several landmark trials delineating treatment regimens that reduce morbidity and mortality. As with any chronic disease, patients with HF are prone to exacerbation of symptoms, prompting investigation into the role of telehealth management implementation. Goldberg et al. published an RCT in 2003, which included 280 patients and reported a 56.2 % reduction in mortality at 6 months within the intervention group that utilized a telemonitoring system (AlereNet system). However, no significant difference in hospitalization rates was found [23] .

In 2010, The New England Journal of Medicine published the Tele-HF trial, a large, multicenter RCT aimed at evaluating the effectiveness of telemonitoring in HF patients [24]. Over 1600 patients underwent randomization, and 826 were included in the intervention group. In addition to usual care, these patients received a Pharos Tel-Assurance device that gave them access to an automated phone messaging system to record their daily symptoms. The results were reviewed by clinicians every weekday, and any unusual symptoms prompted the clinician to call the patient and recommend further intervention if deemed necessary. The remaining patients included in the usual care group were given regular physician follow-up, HF educational material, and a scale for weight monitoring. Overall, the median age of study participants was 61, and over 70 % of participants had an ejection fraction less than 40 % with largely New York Heart Association (NYHA) class II and III symptom manifestations [24]. After 6 months of evaluation, there was no statistically significant difference found in time to readmission for HF, all-cause readmission, number of readmissions, hospital days, or mortality. It should be noted that the adherence rate in the telemonitoring group dropped from ~ 90 % in the first week to ~ 50 % by week 26, which is comparable to “real-life” adherence rates [24]. Additionally, no difference was noted in subgroup analyses including NYHA class, gender, age (< 65 or ≥ 65), race, or ejection fraction . A German trial, TIM-HF, published in 2011, used mobile devices for blood pressure, weight, and electrocardiogram (EKG) monitoring and also found no difference in all-cause mortality in “remote telemedical management,” [25] as opposed to usual care.

A meta-analysis by Clark et al. reviewed 13 studies in 2011 that evaluated the effectiveness of telemedicine in HF management. Out of the studies evaluated, 10 used mortality as a primary endpoint, and 5 of these showed a reduction in mortality favoring telehealth monitoring [26]. These studies consisted of a reasonable study group size of at least greater than 80 patients [23, 26]. Overall, the meta-analysis showed no difference in hospitalization rates with the use of telehealth monitoring, although the power to detect a difference may have been limited by a significant drop in admission rates in the beginning of the study period, although this eventually tapered off. Patients in the telemonitoring groups were reported to have significant improvement in quality of life , as measured by the Minnesota Living with Heart Failure and Short Form questionnaires [26–28] .

In 2014, Feltner et al. reviewed 47 trials regarding the use of transitional care strategies in the management of HF which included home visits, structured telephone support, telemonitoring, and clinic-based follow-up. A significant reduction in morality and HF-specific hospital admission rates was identified over the 6-month study period in patients that received structured telephone support [29]. Overall, the data for the use of telehealth strategies in HF management have not demonstrated reproducible improvements in hospitalizations and readmission rates in this population. However, the possibility of mortality benefit and improvement in quality of life using telehealth warrants more investigation in this area. Standardization of techniques employed will be necessary to gain conclusive information .

HTN affects approximately 32.5 % adults over the age of 18 in the USA [30]. It has been well documented that uncontrolled HTN is associated with significantly increased cardiovascular risk and morbidity/mortality related to end-organ damage [31]. It has been identified as the “silent killer,” battled by primary care clinicians every day. Blood pressure values fluctuate with stress, anxiety (white coat HTN), pain, and discomfort; therefore, in-office readings may not provide the most accurate depiction of blood pressure control, thus establishing a specific role for home blood pressure monitoring and telehealth interventions [31] .

Abudagga et al. reviewed 15 studies on this topic, including ten RCTs, with a range of telemonitoring devices including self-blood pressure monitoring and phone reporting, blood pressure monitoring devices that link to web-based technologies accessible by clinicians, and 24 ambulatory devices [31]. Study durations ranged from 8 weeks to 2 years, and participant mean ages ranged from 51 to 76. The authors concluded that telemonitoring resulted in significant improvement of blood pressure, with reductions in systolic blood pressure by at least 10 points in six of the studies reviewed. Unfortunately, there are several limitations to these studies. Compliance with use of the monitoring devices was noted to decline over time, medication compliance was not addressed and could not be adequately assessed in many studies, and cost-effectiveness was largely not studied. Four of the aforementioned investigations addressed quality of life as a secondary end point and noted no significant difference [31]. A 2010 systematic review by Pare et al. on telemanagement of chronic diseases that included 17 HTN studies, also reported that research favors improvement in HTN management with the use of telehealth technology evidenced by reduction in systolic and diastolic blood pressure [4] .

As previously mentioned, uncontrolled HTN negatively affects various disease processes, significantly impacting morbidity. The relationship between HTN control and diabetes and how it correlates with risk reduction is well documented, and current guidelines support more intensive control in this group of patients with these chronic diseases [32]. A Canadian study published in 2012 included 110 diabetic patients who were randomized to self-care support, that is, telemonitoring (n = 55) or control (n = 55). This study utilized 24 ambulatory devices that submitted blood pressure data over Bluetooth to a smartphone. Patients in the intervention group, in addition to usual care and regular follow-up, received electronic messages alerting them if their blood pressure was in the target range, and if values were outside the range, they would be prompted to contact their clinician. Subjects were monitored for 1 year. In this study, telemonitoring was associated with a mean decrease of 7.1 mmHg in systolic pressure compared to controls (p < 0.005). Furthermore, 51 % participants in the self-monitoring group reached their target blood pressure of < 130/80 as compared to 31 % of control subjects [33] .

The data regarding telemonitoring, as related to HTN management, support the notion that these interventions are efficacious in reducing blood pressure. Of the literature reviewed, little data speak to the cost-effectiveness of these strategies. In an outpatient Scottish study in 2013, the clinical benefit of telemonitoring in blood pressure management was also confirmed, but with an associated significant increase in cost as compared to usual care [34]. That said, the duration of the study was brief (6 months) and cannot speak to future, long-term implications regarding decreased health-care costs as a result of risk reduction from improved blood pressure control .

IBD encompasses two disease entities, Crohn’s disease and ulcerative colitis (UC). It is estimated that 1.4 million Americans suffer from IBD [35]. The disease course includes periods of remission and times of exacerbation, which can be extremely distressing to patients and diminish their quality of life . [36]. Multiple treatment regimens are available; however, medication noncompliance is a recurrent challenge in this population, resulting in high rates of relapse and increased health-care resource utilization [36]. Cross et al. published a pilot study in 2007 that included 25 patients to evaluate the feasibility of Home Automated Telemanagement (HAT) utilization [37]. Patients were required to do weekly self-testing in the form of a symptom diary via multiple-choice testing on a secure server. Data alerts were set to notify clinicians based on symptom scoring. In addition to self-monitoring, their software also included educational facts related to their disease from the Crohn’s and Colitis Foundation, with related follow-up questions. This study reported 91 % of patients were complaint with the technology. The authors noted a decrease in the clinical disease activity using the Harvey Bradshaw Index [38] as well as a decrease in serologic inflammatory markers at 6 months follow-up. An improvement in quality of life was also reported, demonstrated by an overall increase in IBD-specific quality of life scores as measured by the Short Inflammatory Bowel Disease Questionnaire (SIBDQ) [37, 39].