Research Article

Experience with Activity Monitors of Patients with COPD, Sarcoidosis and Pulmonary Fibrosis in the Netherlands

CMR Hendriks^1,2,3, DD Deenstra^1,4, MDP Elfferich^1,5, B Strookappe^1,5, PAHM Wijnen^1,6, J De Vries^1,7,8 and M Drent^1,2,9*

¹ild care foundation research team, Ede, The Netherlands

²ILD Center of Excellence, Department of Pulmonology, St. Antonius Hospital, Nieuwegein, The Netherlands

³Faculty of Medicine, Utrecht University, The Netherlands

⁴Department of Respiratory Medicine, Catharina Hospital, Eindhoven, The Netherlands

⁵Department of Physical Therapy, Hospital Gelderse Vallei, The Netherlands

⁶Department of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Centre, The Netherlands

⁷Department of Medical Psychology, Elisabeth-TweeSteden Hospital Tilburg, The Netherlands

⁸Department of Medical and Clinical Psychology, Tilburg University, The Netherlands

⁹Department of Pharmacology and Toxicology, Maastricht University, The Netherlands

Submission: July 16, 2019; Published: Auguts 06, 2019

*Corresponding author: Prof. Marjolein Drent, ILD Center of Excellence, Department of Pulmonology, St Antonius Hospital, Koekoekslaan 13435 CM Nieuwegein, The Netherlands

How to cite this article: CMR Hendriks, DD Deenstra, MDP Elfferich, B Strookappe, PAHM W, et al. Experience with Activity Monitors of Patients with COPD, Sarcoidosis and Pulmonary Fibrosis in the Netherlands. Psychol Behav Sci Int J. 2019; 12(4): 555843. DOI: 10.19080/PBSIJ.2019.12.555843.

Abstract

Purpose: Physical activity (PA) offers great health benefits for a wide range of conditions. Critical factors for PA are motivation and encouragement. The aim of this study was to evaluate self-reported experiences with PA and activity monitors among Dutch patients suffering from chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, or sarcoidosis.

Study design: Patients’ experiences with PA and various activity monitors were evaluated using an online survey addressing the use and possible benefits of activity monitors, conducted among Dutch patients with COPD, sarcoidosis or pulmonary fibrosis, in cooperation with Dutch patient societies.

Results: A total of 1160 patients completed the survey: 460 with COPD, 467 with sarcoidosis, and 233 with pulmonary fibrosis. The majority of patients (95%) emphasized that exercise and PA was beneficial to them. Professional supervision of PA was reported by 39.1% of the COPD patients, 28% of the sarcoidosis patients, and 40.9% of the patients with pulmonary fibrosis. Patients using activity monitors (n=267; 23%) reported having better insights into their daily performance and activity (80%) and feeling encouraged to accomplish more PA (76%).

Conclusion: This study showed that PA is beneficial to a majority of patients suffering from COPD, sarcoidosis or pulmonary fibrosis. Using activity monitors (almost one-quarter: 23%) stimulated patients to be more physically active and provided them with a better understanding of their disease, thereby improving their self-management and behavior. Further research is needed to explore the role of self-monitoring in improving patient empowerment and self-care.

Keywords: Activity Monitor, Behavior, COPD, Disability, Physical Activity, Pulmonary Fibrosis, Sarcoidosis, Self-Monitoring

Introduction

There is worldwide consensus about the health benefits of regular engagement in physical activity (PA) of at least moderate intensity [1]. Therefore, many countries have introduced initiatives to improve population PA levels [2]. Research in chronically ill patients has shown that exercise improves quality of life (QoL) and is beneficial to patients suffering from a wide range of chronic symptoms, such as fatigue, reduced exercise tolerance, muscle weakness and dyspnea [3,4]. Among these chronically ill patients are patients with chronic obstructive pulmonary disease (COPD), sarcoidosis and pulmonary fibrosis. Exercise tolerance and daily PA proved to be predictors of Qol and survival in chronic pulmonary diseases such as COPD [5,6]. In line with this, research found that impaired exercise tolerance, fatigue and muscle weakness appeared to have a negative influence on the QoL of patients with sarcoidosis and pulmonary fibrosis [7-13].

Motivation is a critical factor in pursuing and continuing to pursue PA. Intrinsic participation motivates patients to continue PA or helps to achieve goals associated with PA, such as affiliation and social engagement, challenge and skills development. Increased perceived competence for PA also has positive predictive value for more adaptive exercise behavioral outcomes clearly associated with greater exercise participation [14]. Behavioral strategies to enhance PA self-monitoring, such as logging walking activity and using pedometers to track step counts, have been shown to improve health-related outcomes [15]. The use of wearable technologies, such as the Fitbit, is becoming increasingly common among the general public [1]. In addition, understanding one’s own disease mechanism is important in self-management and patient empowerment. Self-management is important because people want an approach targeted to their own personal goals, situation and behavior.

The aim of this study was to evaluate self-reported experiences with physical activity and activity monitors among Dutch patients suffering from COPD, pulmonary fibrosis or sarcoidosis.

Methods

Study Design

In cooperation with the Lung Foundation Netherlands, the Dutch Sarcoidosis Society (Sarcoidose.nl ), the Dutch Pulmonary Fibrosis Society and the ild care foundation, the authors designed a cross-sectional web-based anonymous questionnaire that broadly investigated experiences (if any) with self-initiated physical activity, such as exercising in a gym, walking, biking, playing golf, or gardening, as well as the use of activity monitors. Recruitment took place from October 2017 to April 2018 and was designed to engage large representative samples of all three patient populations.

Study Subjects and Procedure

Patients were recruited from among the membership of the Lung Foundation Netherlands, the Dutch Sarcoidosis Society (Sarcoidose.nl) and the Dutch Pulmonary Fibrosis Society, using the societies’ newsletters, and newsletters of the ILD Center of Excellence at Nieuwegein. No incentives were offered. To participate, patients had to be proficient in Dutch and have internet access. Patients were provided with a specific link to the survey by the online questionnaire tool Surveymonkey (www.surveymonkey.com). The survey queried experiences regarding physical activity, experiences with the use of various self-purchased activity monitors, and demographics (gender and age).

Statistical Analysis

Statistical analysis was performed using SPSS 20 (SPSS, Chicago, Illinois) software. Standard descriptive statistics were computed. ANOVA was used for comparison between the COPD, sarcoidosis and fibrosis patient samples. Outcomes of the questionnaires are presented as mean ±SD unless stated otherwise. Statistical significance was assumed at p<0.05.

Results

In total, 1160 patients completed the survey: 460 with COPD, 467 with sarcoidosis, and 233 with pulmonary fibrosis. Almost all (95%) reported exercise and PA to be beneficial to their health. Professional supervision of PA was reported by 39.1% of the COPD patients, 28% of the sarcoidosis patients and 40.9% of the patients with pulmonary fibrosis (Table 1), and 28% of the study participants were involved in a rehabilitation program or were supervised by a physical therapist. Twenty-three percent had experience with one or more activity monitors. Activity monitors offered patients information about their daily performance and activity levels (80%) and encouraged them to pursue more PA (76%; table 2). Seventy-six percent of the users reported that wearing an activity monitor offered benefits in addition to their medication (76%). As regards the type of activity monitor used, pedometers were reported to be less user-friendly and less reliable than the more advanced instruments such as Fitbit.

COPD=chronic obstructive pulmonary disease; SD=standard deviation; NS=not significant

Of the non-users (n=893), 58% indicated that they would consider using an activity monitoring device in the future if it was reimbursed by their health insurance, while 16.6% were not interested at all in using an activity monitor in the future. The use of activity monitoring stimulated patients’ engagement in PA and improved their understanding of their disease across all three patient samples. Although the sarcoidosis patients reported the smallest benefits from the use of an activity monitor (with 45.8% reporting that it “makes me feel fitter” vs. 61.6 and 64.5% for COPD and pulmonary fibrosis patients, respectively), they were the most positive about using activity monitors (Table 2). A large majority of the users would recommend activity monitoring to other patients. Forty percent of the users would appreciate contacts with fellow patients to exchange experiences.

COPD=chronic obstructive pulmonary disease; SD=standard deviation; NS=not significant

Discussion

The majority of patients in our survey (95%) reported pursuing physical activities and exercise as they assumed these to be beneficial to their health condition. They engaged in some type of leisure-time activity, such as walking, exercising in a gym, biking, playing golf, or gardening. Professional supervision of PA was reported by 39.1% of the COPD patients, 28% of the sarcoidosis patients and 40.9% of the patients with pulmonary fibrosis. Although benefits of physical training were reported by almost all (95%), only 28% reported that they were supervised by a physical therapist or took part in a rehabilitation program, and nearly one-quarter (23%) used an activity monitor. This latter group indicated that it stimulated them to be more physically active and provided them with greater insights into their disease. The success of using an activity monitor depended on whether it was user-friendly. An appropriate activity monitor was useful both to stimulate and improve self-management, and change the behavior of patients with COPD, sarcoidosis, or pulmonary fibrosis. Only about a quarter reported using an activity monitor, and it can be expected that even greater benefit could be achieved if more patients used such a device.

A sedentary lifestyle and lack of PA are well-established risk factors for chronic disease and adverse health outcomes. Even small increases in levels of PA can have a significant impact on chronic disease risk and premature death, especially for people with the lowest levels of physical fitness [16]. Studies exploring walking exercise have found that those who walked at least two hours a week had a 39% lower all-cause mortality rate than those walking less than two hours a week [17]. PA monitors provide patients with information about their PA because of their ability to measure activity continuously under real-life conditions [13]. PA monitors are currently widely used by the general public. Studies have shown several positive effects of activity trackers, such as increases in daily PA, improvement of self-efficacy and motivation, higher QoL levels (in COPD patients) [5,18,19] and less fatigue in ILD and sarcoidosis patients [13,20,21]. Studies of patients with obesity [22,23] and diabetes [24] showed similar promising results. Recently, Gill et al. [25] demonstrated that HealtheSteps™, a lifestyle prescription program for patients suffering from chronic diseases, was effective at increasing PA (in terms of step counts per day), decreasing weekday sitting time (min/day) and improving healthy eating behaviors [25].

The program comprised the use of eHealth technology devices (Healthesteps app, telephone coaching and a private HealtheSteps social network) as well as in-person lifestyle coaching. The results showed that patients who engaged in the program (n=59) had increased their daily physical activity by 3132 steps/day more than the comparator group at 6-months follow-up. Moreover, they reported improved self-rated health (on the EuroQol Visual Analog Scale, EQ-VAS). Their study showed that activity monitoring devices (such as activity tracking apps) together with personal lifestyle coaching can effectively increase physical activity levels and lead to positive health behavior changes in patients with chronic diseases [25].

Although many studies have reported short-term positive effects of PA interventions, including pedometer-based interventions [26-28], long-term health effects require sustained PA changes [18], and evidence for maintenance is scarce. Recently, Harris et al. [18] showed the long-term success of these interventions. They had previously reported increased PA-levels at 12 months following 12-week pedometer-based walking interventions for adults and older adults recruited through primary care and delivered either by post with minimal support or through nurse-led PA consultation. The follow-up study demonstrated that higher levels of objectively measured PA were still present at 3-4-years follow-up, including an increase in additional steps/day of between 400 and 600, depending on the program attended (postal vs. nurse) in the intervention group compared with the control group [18]. Gill et al. [25] also reported positive results concerning the maintenance of PA changes; activity level and self-rated health (EQ-VAS) were higher in the intervention groups compared to the control group at 12- and 18-months follow-up [25]. These studies corroborate the positive effects of PA intervention programs and PA-tracking devices on patients’ health and well-being in the long term. In the present study we found that patients were more encouraged by the more advanced activity monitors compared with the simple pedometer. This is in line with an earlier study, showing that a Fitbit is better accepted and associated with increased PA compared to a standard pedometer [29].

In general, a substantial number of COPD, sarcoidosis, and pulmonary fibrosis patients are disabled by functional impairments due to disease-associated symptoms, especially fatigue, reduced exercise capacity, muscle weakness and pain [9,30,31]. Sarcoidosis patients have indicated less improvement of their physical wellbeing compared to patients suffering from COPD or pulmonary fibrosis. This might be explained by the fact that sarcoidosis patients are more severely impaired by fatigue than the other two categories, even after all signs of disease activity have disappeared [32-34]. Functional impairments are defined as limitations in, or inability to perform, certain physical activities, such as walking and lifting, or mental activities such as concentrating, remembering tasks, and conflict handling. However, patient follow-up often fails to pay attention to these functional impairments and tends to concentrate on medical parameters as disease-severity indicators, such as the results of pulmonary function tests and imaging [10,35]. A multidisciplinary approach is recommended and should include gathering information about physical as well as psychological health, using muscle and exercise testing, performance tests, and validated questionnaires like the Fatigue Assessment Scale (FAS) and the subjective Cognitive Failure Questionnaire (CFQ) [10,32,36-41]. Data derived from activity tracking devices could be very useful and help patients and physicians assess disease burden and activity levels over time. There is an urgent need for more information and guidelines to assess the physical and mental capacities of patients with COPD, sarcoidosis, and pulmonary fibrosis, to ensure that lung function is not the only aspect taken into account [35].

Physical inactivity leads to high health service costs and is the fourth leading risk factor for mortality worldwide [4,18]. People use activity monitors to estimate their PA, such as distance covered or calories burned, based on step counts and sleep monitoring, and these trackers have been found to be relatively accurate and beneficial for such purposes. Increased PA facilitated by these devices could lead to clinical paybacks at low cost [19]. Although the clinical effectiveness of PA in ILD and COPD is increasingly understood, explaining the cost-effectiveness of PA guided by activity monitors can motivate involved parties and policy makers to ensure that this device/intervention is widely available [37]. These devices, along with their close integration with Apple Health and Google Fit platforms, can significantly help improve the QoL of patients and help integrate mobile technology into efforts to reduce many health problems. In the present study more than half of the patients who did not have an activity monitor would consider using it if it was reimbursed by their health insurance. It would be very interesting to evaluate in a future study whether health care benefits can be achieved from the use of activity monitors, and whether this would reduce health care costs.

Limitation

A major limitation of this study is that the data were self-reported by the participants. Corresponding objective data on patients’ illness severity would have been very helpful. However, the aim of this study was not to evaluate the severity of the diseases, but to find out whether the sample we studied used activity monitors in general. The importance of patient participation in healthcare has been increasingly acknowledged [39,42], so studies from a patient’s perspective are important. There is nevertheless a clear need for future studies combining both aspects.

Conclusion

The majority of patients we studied (95%) reported pursuing physical activities and exercise, which they regarded as being beneficial to their health condition. There was no difference in this respect between the various disorders. Professional supervision of PA was reported by 39.1% of the COPD patients, 28% of the sarcoidosis patients and 40.9% of the patients with pulmonary fibrosis. Almost one quarter of the included patients had experience with an activity monitor. Patients using activity monitors (n=267; 23%) reported having greater insight into their daily performance and activity (80%) and feeling encouraged to accomplish more PA (76%). We should embrace the use of activity monitors to meet the challenge of motivating and encouraging people to get moving. An activity monitor is useful to stimulate and improve self-management. Further research is needed to explore the role of self-monitoring with activity monitors, in addition to regular check-ups, in improving patient empowerment and patient care.

Acknowledgement

The authors wish to thank the Lung Foundation Netherlands (www.longfonds.nl), the Dutch Sarcoidosis Society: Sarcoidose.nl (www.sarcoidose.nl) , the Dutch Pulmonary Fibrosis Society (www.longfibrose.nl), and all participants in this study for all their efforts.

Author Contributions

All authors were involved in the design of the study and data collection. CH, DD, and MD analyzed the data and drafted the manuscript. ME, BS, PW, and JDV revised it critically for important intellectual content. All authors read and approved the final manuscript.

Funding

This study was supported by a research grant of the ild care foundation: www.ildcare.nl. The study sponsor had no involvement in the study design; in the collection, analysis, and interpretation of data; in the writing of the manuscript; or in the decision to submit the manuscript for publication.

Data Availability

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no competing interests.

In accordance with the Dutch Medical Research Involving Human Subjects Act, the Medical Ethics Committee of St. Antonius Hospital Nieuwegein waived formal approval by the Committee.

References

1. Haskell WL, Lee IM, Pate RR, Powell KE, Blair SN, et al. (2007) Physical activity and public health: updated recommendation for adults from the American College of Sports Medicine and the American Heart Association. Med Sci Sports Exerc 39(8): 1423-1434.
2. Reis RS, Salvo D, Ogilvie D, Lambert EV, Goenka S, et al. (2016) Scaling up physical activity interventions worldwide: stepping up to larger and smarter approaches to get people moving. Lancet 388(10051): 1337-1348.
3. McGuire S (2014) Centers for Disease Control and Prevention. State indicator report on physical activity, 2014. Atlanta, GA: U.S. Department of Health and Human Services; 2014. Adv Nutr 5(6): 762-763.
4. Lee IM, Shiroma EJ, Lobelo F, Puska P, Blair SN, Katzmarzyk PT (2012) Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy. Lancet 380(9838): 219-229
5. Bertici N, Fira-Mladinescu O, Oancea C, Tudorache V (2013) The usefulness of pedometry in patients with chronic obstructive pulmonary disease. Multidiscip Respir Med 8(1): 7.
6. Yohannes AM, Baldwin RC, Connolly M (2002) Mortality predictors in disabling chronic obstructive pulmonary disease in old age. Age Ageing 31(2): 137-140.
7. Drent M, Wirnsberger RM, Breteler MH, Kock LM, de Vries J, Wouters EF (1998) Quality of life and depressive symptoms in patients suffering from sarcoidosis. Sarcoidosis Vasc Diffuse Lung Dis 15(1): 59-66.
8. De Vries J, Drent M (2006) Quality of life and health status in interstitial lung diseases. Curr Opin Pulm Med 12(5): 354-358.
9. Swigris JJ, Kuschner WG, Jacobs SS, Wilson SR, Gould MK (2005) Health-related quality of life in patients with idiopathic pulmonary fibrosis: a systematic review. Thorax 60(7): 588-594.
10. Grunewald J, Grutters JC, Arkema EV, Saketkoo LA, Moller DR, Müller-Quernheim J (2019) Sarcoidosis. Nature Reviews Disease Primers 5(1): 45.
11. Voortman M, Hendriks CMR, Lodder P, Drent M, De Vries J (2019) Quality of life of couples living with sarcoidosis. Respiration (In press).
12. De Vries J, Kessels BL, Drent M (2001) Quality of life of idiopathic pulmonary fibrosis patients. Eur Respir J 17(5): 954-961.
13. Cho PSP, Vasudevan S, Maddocks M, Spinou A, Chamberlain Mitchell S, et al. (2019) Physical inactivity in pulmonary sarcoidosis. Lung 197(3): 285-293.
14. Teixeira PJ, Carraca EV, Markland D, Silva MN, Ryan RM (2012) Exercise, physical activity, and self-determination theory: a systematic review. Int J Behav Nutr Phys Act 9: 78.
15. Richardson CR, Goodrich DE, Larkin AR, Ronis D, Holleman RG, Damschroder LJ, Lowery JC (2016) A comparative effectiveness trial of three walking self-monitoring strategies. Transl J Am Coll Sports Med 1(15): 133-142.
16. Warburton DE, Nicol CW, Bredin SS (2006) Health benefits of physical activity: the evidence. CMAJ 174(6): 801-809.
17. Gregg EW, Gerzoff RB, Caspersen CJ, Williamson DF, Narayan KM (2003) Relationship of walking to mortality among US adults with diabetes. Arch Intern Med 163(12): 1440-1447.
18. Harris T, Kerry SM, Limb ES (2018) Physical activity levels in adults and older adults 3-4 years after pedometer-based walking interventions: Long-term follow-up of participants from two randomised controlled trials in UK primary care. PLoS Med 15(3): e1002526.
19. Mendoza L, Horta P, Espinoza (2015) Pedometers to enhance physical activity in COPD: a randomised controlled trial. Eur Respir J 45(2): 347-354.
20. Lorig KR, Ritter PL, Gonzalez VM (2003) Hispanic chronic disease self-management: a randomized community-based outcome trial. Nurs Res 52(6): 361-369.
21. Spruit MA, Singh SJ, Garvey C (2013) An official American Thoracic Society/European Respiratory Society statement: key concepts and advances in pulmonary rehabilitation. Am J Respir Crit Care Med 188(8): e13-64.
22. Cheatham SW, Stull KR, Fantigrassi M, Motel I (2018) The efficacy of wearable activity tracking technology as part of a weight loss program: a systematic review. J Sports Med Phys Fitness 58(4): 534-548.
23. Benedetti MG, Di Gioia A, Conti L, Berti L, Degli Esposti L, et al. (2009) Physical activity monitoring in obese people in the real life environment. J Neuroeng Rehabil 6: 47.
24. Cooke AB, Pace R, Chan D, Rosenberg E, Dasgupta K, et al. (2018) A qualitative evaluation of a physician-delivered pedometer-based step count prescription strategy with insight from participants and treating physicians. Diabetes Res Clin Pract 139: 314-322.
25. Gill DP, Blunt W, Boa Sorte Silva NC, Stiller-Moldovan C, et al. (2019) The HealtheSteps lifestyle prescription program to improve physical activity and modifiable risk factors for chronic disease: a pragmatic randomized controlled trial. BMC Public Health 19(1): 841.
26. Bravata DM, Smith-Spangler C, Sundaram V (2007) Using pedometers to increase physical activity and improve health: a systematic review. JAMA 298(19): 2296-2304.
27. Hobbs N, Godfrey A, Lara J (2013) Are behavioral interventions effective in increasing physical activity at 12 to 36 months in adults aged 55 to 70 years? A systematic review and meta-analysis. BMC Med 1175.
28. Kang M, Marshall SJ, Barreira TV, Lee JO (2009) Effect of pedometer-based physical activity interventions: a meta-analysis. Res Q Exerc Sport 80(3): 648-655.
29. Cadmus-Bertram LA, Marcus BH, Patterson RE, Parker BA, Morey BL (2015) Randomized trial of a Fitbit-based physical activity intervention for women. Am J Prev Med 49(3): 414-418.
30. Marcellis RG, Lenssen AF, de Vries J, Drent M (2013) Reduced muscle strength, exercise intolerance and disabling symptoms in sarcoidosis. Curr Opin Pulm Med 19(5): 524-530.
31. Yount SE, Beaumont JL, Chen SY, Kaiser K, Wortman K, et al. (2016) Health-related quality of life in patients with idiopathic pulmonary fibrosis. Lung 194(2): 227-234.
32. Drent M, Strookappe B, Hoitsma E, De Vries J (2015) Consequences of sarcoidosis. Clin Chest Med 36(4): 727-737.
33. Voortman M, Hendriks CMR, Elfferich MDP, Bonella F, et al. (2019) The burden of sarcoidosis symptoms from a patient perspective. Lung 197(2): 155-161.
34. Tavee J, Culver D (2019) Nonorgan manifestations of sarcoidosis. Curr Opin Pulm Med.
35. Hendriks CMR, Saketkoo LA, Elfferich MDP, De Vries J, Wijnen P, et al. (2019) Sarcoidosis and work participation: the need to develop a disease-specific core set for assessment of work ability. Lung 197(4): 407-413.
36. Hendriks C, Drent M, De Kleijn W, Elfferich M, Wijnen P, et al. (2018) Everyday cognitive failure and depressive symptoms predict fatigue in sarcoidosis: A prospective follow-up study. Respir Med 138S: S24-S30.
37. Nakazawa A, Cox NS, Holland AE (2017) Current best practice in rehabilitation in interstitial lung disease. Ther Adv Respir Dis 11(2): 115-128.
38. Strookappe B, Saketkoo LA, Elfferich M, Holland A, De Vries J, et al. (2016) Physical activity and training in sarcoidosis: review and experience-based recommendations. Expert Rev Respir Med 10(10): 1057-1068.
39. van Helmondt SJ, Polish LB, Judson MA, Grutters JC (2019) Patient perspectives in sarcoidosis. Curr Opin Pulm Med.
40. Rajala K, Lehto JT, Sutinen E, Kautiainen H, Myllarniemi M, et al. (2018) Marked deterioration in the quality of life of patients with idiopathic pulmonary fibrosis during the last two years of life. BMC Pulm Med 18(1): 172.
41. Hendriks C, Drent M, Elfferich M, De Vries J (2018) The Fatigue Assessment Scale: quality and availability in sarcoidosis and other diseases. Curr Opin Pulm Med 24(5): 495-503.
42. Moor CC, Gur-Demirel Y, Wijsenbeek MS (2019) Feasibility of a comprehensive home monitoring program for sarcoidosis. J Pers Med 9(2).