The Value of an e-Health Platform in Bariatric Surgery: A Retrospective Study on the Impact on Weight Loss

Abstract

Background:

In this time, where health care is getting more digitalized, opportunities open up to provide patients with additional information using e-Health. An e-Health platform was developed to increase knowledge about obesity in general, bariatric procedures, and follow-up program to achieve more weight loss. It was hypothesized that a higher e-Health usage, defined as page views per patient, leads to a higher percentage total weight loss (%TWL) at 2 years postoperatively.

Materials and Methods

: Accounts with available follow-up data between January 2015 and April 2018 were retrospectively reviewed. Three groups were formed based on number of page views.

Results:

In total, 1,098 subjects were analyzed. On average, a patient connected 12 times with an average of 51-page views per patient. At 1 year postoperatively, the %TWL was 30.7 versus 30.9 versus 31.9 (p = 0.126), and at 2 years 29.4 versus 29.8 versus 30.5 (p = 0.350) in low-active, medium-active, and high-active group, respectively. Analysis whether patients accessed the preoperative content did not show significant differences. However, patients who accessed content after surgery lost more weight than those who did not, being 30.1%TWL versus 31.7%TWL at 1 year (p = 0.006) and 28.9%TWL versus 30.4%TWL at 2 years postoperatively (p = 0.034). Pre- and postoperative quality of life did not differ between groups.

Conclusion:

e-Health might be a beneficial tool for weight reduction after bariatric surgery. The current platform reached a large portion of patients. Patients accessing postoperative content lost more weight at 1 and 2 years postoperatively than those who did not. Quality of life was comparable.

Introduction

Morbid obesity is steadily growing to be one of the greatest threats to human health of the 21st century. Obesity is associated with an increased risk to develop a variety of diseases, including diabetes mellitus, hypercholesterolemia, hypertension, obstructive sleep apnea syndrome, arthralgia, various types of cancers, and probably many more.¹ Besides physical health problems, obesity is also linked to a decline in mental health.^2,3 Bariatric surgery appears to be more effective in terms of sustainable weight loss compared with nonsurgical therapy.^4,5 A successful treatment also includes lifestyle changes such as a healthier diet and more exercise. The concept of support by e-Health in maintenance and commitment in chronic diseases applies perfectly to the bariatric patient. Indeed, various reviews have suggested that e-Health can be a valid addition to standard care for weight loss and weight stabilization; however, its effect in bariatric surgery remains uncertain.^6
–8

We provide all patients who are referred for a bariatric procedure with access to an online e-Health platform. This online environment can be accessed by an internet browser or dedicated app and consists of various types of content, including videos and written information about the bariatric procedures, aftercare program, dietary tips, physical exercise, and more. The purpose of this e-Health platform is to increase understanding of obesity in general, the bariatric procedures, and follow-up program aiming to achieve a better weight reduction and sustainability. It is hypothesized that more intense usage of the e-Health platform, defined as page views per subject, will lead to a higher percentage total weight loss (%TWL) at 2 years postoperatively. In this study, the usage of an e-Health platform and the effects on weight loss and quality of life are assessed in patients undergoing bariatric surgery.

Materials and Methods

A retrospective review was conducted at the obesity center of the Catharina Hospital Eindhoven, the Netherlands, to assess the additional value of an integrated e-Health platform to bariatric surgery. Data were retrieved from patients with accounts created and used between January 2015 and April 2019 with available postoperative weight loss data. Primary outcome was %TWL at 2 years postoperatively. Secondary outcomes were %TWL at other timeframes between 6 months and 3 years postoperatively, baseline characteristics, user data traffic, and quality of life. The setting was a large bariatric center in The Netherlands. Patients were eligible for bariatric surgery if their body mass index (BMI) was at least 40 or 35 kg/m² with obesity-related comorbidity. Patients were screened by a bariatric surgeon, obesity nurses, psychologists, and dieticians. In a multidisciplinary conference the final decision was made whether a patient was eligible for surgery and the intensive postoperative program. All patients got introduced to the e-Health platform and receive a personal account at their first visit to the bariatric center.

e-Health Platform

The e-Health platform was designed by Bepatient^® (SAS Bepatient, Paris, France), an e-Health solution developer. A task force was formed at the obesity center who were responsible for the composition and management of the content on the platform. An introduction video on the contents of the e-Health platform can be seen here (in Dutch): youtu.be/AbafCI1zE4M. This taskforce included a bariatric surgeon, an obesity nurse, a dietician, a psychologist, a physiologist, and a software developer to make sure the platform contained correct information of all these subdivisions. Furthermore, patients were asked about their desires for content and functionalities on the platform. Information was available in the form of written information, fact sheets, images, and videos. Patients had access to the platform after they registered their account and during the duration of the treatment. For patients to receive the first screening appointment, patients were required to fill in the screening questionnaire, which was available on the platform. The answers to these questionnaires were used during the screening appointment. After completing the questionnaire, additional content was accessible. This included basic information about obesity, the bariatric center, different procedures, and the aftercare program.

This subsection was named Preparation phase and was considered to contain essential information by the taskforce. Therefore, this content was pushed to the homepage of all preoperative patients. Furthermore, more in-depth information was available at the Lecture section. Frequently Asked Questions subsections contained answers to various problems or questions of bariatric patients. Also, updates about obesity-related news and changes regarding the obesity center were regularly added in Weekly tips, Question of the week, and fact or false. Patient experiences with the obesity center and operations were available at Patients testimonials. Dieticians posted recipes in accordance with postbariatric needs to stimulate and maintain a healthy diet. Also, instruction videos about several exercises were created by physiotherapist to promote physical activity. The information on the platform was made available in phases. For instance, after the operation date for a patient is set, new content is made available for an individual to see. This way, some content is regarded as either pre- or postoperative. Patients sign a user agreement on the platform that their data are accessible for health care professionals and the platform support team and may be used for scientific research. In addition, informed consent is obtained and signed during the planning of a procedure that health records may also be used for statistical and scientific research. A waiver statement was provided by the local study committee due to the retrospective design and to the fact that all patients had signed a informed consent which was documented in their medical file. The data are stored on an encrypted server and accounts are only accessible with login credentials created by the patient itself. The platform is kept up to date by health care professionals and content is added regularly.

Data Acquirement and Analysis

User activity was retrieved for research purposes. These user data consist of number of page views, number of connections, number of accessed content, and which content was viewed. These data were analyzed in this study. For analyzing health-related outcomes, preoperative and postoperative data such as comorbidity, weight loss and health-related quality of life data from a prospectively kept bariatric database was linked to the user data. Three groups were defined based on the number of page views per patient. Patients who had less than the 33rd percentile of page views were assigned to the low-active group, patients between the 33rd and 66th percentile to the medium-active group and patients who had above 66th percentile were located to the high-active group. Weight loss was reported as %TWL, calculated with the formula: (weight loss/the initial weight) × 100. Health-related quality of life was assessed using a Dutch version of RAND-36-item questionnaire.^9,10 The questionnaire is divided in nine subdomains. All scores are transformed to a 0 (low score) to 100 (high score) scale. Groups were compared using Student's t test, analysis of variance test, and χ² test for normal distribution or Mann–Whitney U tests for non-normal distribution. Multivariate linear regression analysis was performed for variables to adjust for possible confounders such as gender, procedure, and age. All tests were two-tailed, and results with a p < 0.05 were considered statistically significant.

Results

In total, the data of 1,098 patients were available for analysis. Data traffic analyses are displayed in Table 1. The total number of connections to the platform was 13,103 and ranged from 1 up to 237. The mean number of connections per account was 12. The total number of page views from the start of the platform was 56,033. Total page views ranged from 3 up to 608. The mean was 51-page views. Around 82% of all accounts, which were created, connected more than once. Preoperative content was accessed by 66%, postoperative content by 67%, and 54% accessed both pre- and postoperative content. The top three most frequently visited subcategories were (1) Preparation phase, with a total of 13,879 page views, or 28% of all page views, ranging from 0 up to 206 views per patient; (2) Lectures about obesity, with a total of 9,245 page views, or 19% of all page views, ranging from 0 up to 250 views per patient; and (3) Frequently asked questions section, with a total of 6,049 page views, or 12% of all page views, ranging from 0 up to 108 views per patient. The two least viewed subcategories were Patient testimonials and Weight regain prevention, both with <1% of all page views. Those, however, were only added to the platform in the months before this analysis. The top three subsections that had the most unique visitors were (1) Information messages, which 94% of all patients visited at least once; (2) Videos, which 68% of all patients visited; and (3) Preparation phase, which was visited by 66% of all patients. The mean number of subsections visited by patients was 4.0. In terms of reach, ∼3% of all patients visited no subsections, other than the mandatory screenings questionnaire, almost half of all patients visited 1–3 subsections, whereas 36% visited 4–6 sections, 14% visited 7–9, and 2% visited >10 subsections on the platform. Data of all other subcategories can be found in Table 1.

Table 1.

Data Traffic Analysis

	N	%	MEAN ± SD	RANGE
Total activated accounts	1,098	100	—	—	—	—
Total connections	13,103	—	11.9 ± 18.0	1–237	—	—
Total page views	56,033	—	51.0 ± 63.1	3–608	—	—
Connected more than once	904	82	—	—	—	—
Activity
Preoperative content	727	66
Postoperative content	735	67
Pre- and postoperative content	582	54

SUBSECTIONS	PAGE VIEWS	% OF TOTAL	MEAN ± SD	RANGE	UNIQUE VISITORS	%
Preparation phase	13,879	28	12.6 ± 20.1	0–205	727	66
Lectures	9,245	19	8.4 ± 21.8	0–250	250	23
Question of the week	6,047	12	5.5 ± 11.7	0–113	485	44
Frequently asked questions	6,049	12	5.5 ± 10.9	0–108	388	35
Videos	5,926	12	5.4 ± 7.3	0–48	741	68
Information messages	3,892	8	3.3 ± 2.3	0–14	1,037	94
Weekly tips	2,128	4	1.9 ± 4.5	0–54	472	43
Fact or false	1,612	3	1.5 ± 5.9	0–60	166	15
Sports program	593	1	0.5 ± 3.8	0–51	57	5
Weight regain prevention	274	1	0.2 ± 1.2	0–14	74	7
Patient testimonials	133	0	0.1 ± 0.7	0–13	49	5
No. of subsections visited	4,446	—	4.0 ± 2.3	0–11	—	—
None	—	—	—	—	31	3
1–3	—	—	—	—	492	45
4–6	—	—	—	—	400	36
7–9	—	—	—	—	152	14
10 or more	—	—	—	—	23	2

Baseline characteristics of low-, medium-, and high-active groups are shown in Table 2. The three groups were around the same size with 354 patients in the low-active group, 378 in the medium-active group, and 366 in the high-active group. About 21% of the patients who created an account were male. The prevalence of males was 23% versus 22% versus 18% in the low-, medium-, and high-active groups, respectively (p = 0.209). The mean age was 45.9 years. This was 43.7 years in the low-active group, 45.4 years in the medium-active group, and 47.8 years in the high-active group (p < 0.001). Mean preoperative weight was 121.7 kg and mean preoperative BMI was 42.5. Both were not statistically different between groups (p = 0.666 and p = 0.838, respectively).

Table 2.

Baseline Characteristics of Patients Analyzed in Comparing Different Levels of e-Health Activity

	LOW-ACTIVE	MEDIUM-ACTIVE	HIGH-ACTIVE	ALL	p
	MEAN ± SD/% (n)	MEAN ± SD/% (n)	MEAN ± SD/% (n)	MEAN ± SD/% (n)	p
No. of subjects	354	378	366	1,098	—
Gender, male	23 (82)	22 (85)	18 (66)	21 (233)	0.184
Age, years	43.7 ± 12.3	45.4 ± 11.4	47.8 ± 8.9	45.6 ± 11.1	0.000
BMI, kg/m²	42.6 ± 5.6	42.5 ± 5.2	42.4 ± 5.2	42.5 ± 5.3	0.838
Weight, kg	121.8 ± 20.1	122.2 ± 18.6	121.0 ± 17.9	121.7 ± 19.2	0.666
Highest weight, cm	126.3 ± 21.5	127.1 ± 19.1	126.4 ± 18.5	126.6 ± 19.7	0.847
Waist circumflex, cm	128.3 ± 13.9	127.3 ± 13.2	127.7 ± 12.6	127.7 ± 13.2	0.606
Comorbidity
Hypertension	32 (113)	34 (127)	34 (123)	33 (363)	0.858
Diabetes	16 (57)	15 (55)	16 (58)	15 (170)	0.822
Dyslipidemia	17 (60)	15 (58)	20 (72)	17 (190)	0.289
GERD	30 (107)	32 (119)	31 (115)	31 (341)	0.919
OSAS	12 (44)	15 (57)	19 (69)	15 (170)	0.057
Arthralgia	61 (214)	59 (221)	61 (222)	60 (657)	0.797
Procedure					0.148
Gastric sleeve	66 (233)	65 (245)	60 (215)	64 (693)
Gastric bypass	34 (120)	35 (131)	40 (146)	36 (397)

BMI, body mass index; GERD, gastroesophageal reflux disease; OSAS, obstructive sleep apnea syndrome.

In Table 3, weight loss outcomes related to different levels of activity on the platform are shown. The %TWL after 2 years was 29.4 versus 29.8 versus 30.5 versus low-, medium-, and high-active groups, respectively (p = 0.317) The highest %TWL was seen in the high-active group in all follow-up time frames; however, this was not statistically significant. In regard to whether or not patients had preoperative activity on the platform, no statistically significant differences were seen in %TWL in the 3 years of follow-up (see Table 4). However, in terms of postoperative activity, patients who accessed the postoperative content had a significantly higher %TWL at 1 and 2 years postoperative. At 1 year postoperatively patient who accessed postoperative content had 31.7%TWL compared with 30.1%TWL for those who did not (p = 0.006). This remained statistically significant after multivariate linear regression analysis (p = 0.005) of gender, type of procedure, and age. At 2 years postoperatively this was 30.4%TWL compared with 28.9%TWL (p = 0.034). After adjusting for previously mentioned confounders this also remained statistically significant (p = 0.049).

Table 3.

Weight Loss Outcomes

%TWL	LOW-ACTIVE	MEDIUM-ACTIVE	HIGH-ACTIVE	pALL GROUPS	pLOW-ACTIVE AND MEDIUM-ACTIVE	pLOW-ACTIVE AND HIGH-ACTIVE	pMEDIUM-ACTIVE AND HIGH-ACTIVE
6 months (n = 1,087)	20.7 ± 6.3	20.2 ± 5.4	21.1 ± 5.7	0.124	0.219	0.462	0.035
1 year (n = 1,073)	30.7 ± 8.9	30.9 ± 8.5	31.9 ± 8.9	0.137	0.703	0.066	0.126
2 years (n = 938)	29.4 ± 9.6	29.8 ± 9.6	30.5 ± 9.6	0.317	0.558	0.134	0.350
3 years (n = 483)	27.3 ± 9.7	27.9 ± 9.8	28.5 ± 9.9	0.556	0.584	0.281	0.581

%TWL, percentage total weight loss.

Note: Weight loss outcomes displayed as %TWL after bariatric procedure comparing three groups of subjects with different levels of activity on an e-Health platform.

Table 4.

Weight Loss Outcomes, Comparing Pre- and Postoperative Activity

%TWL	PREOPERATIVE CONTENT		p	POSTOPERATIVE CONTENT		p
%TWL	NO	YES	p	NO	YES	p
6 months (n = 1,087)	20.7 ± 5.7	20.7 ± 5.8	0.999	20.4 ± 6.1	20.8 ± 5.6	0.224
1 year (n = 1,073)	30.9 ± 8.7	31.4 ± 8.8	0.446	30.1 ± 8.5	31.7 ± 8.8	0.006
2 years (n = 938)	29.9 ± 9.5	29.9 ± 9.7	0.987	28.9 ± 9.5	30.4 ± 9.6	0.034
3 years (n = 483)	27.8 ± 10.0	27.9 ± 9.7	0.956	27.2 ± 10.3	28.2 ± 9.5	0.336

Note: Weight loss outcomes displayed as %TWL after bariatric procedure comparing groups based on preoperative and postoperative activity.

Health-related quality of life results are displayed in Table 5. Overall preoperative quality of life was poor and the mean scores of all domains were worse compared with a reference group of Dutch citizens.⁹ Across all domains in all groups major improvements were seen. However, no statistically significant differences were seen between groups.

Table 5.

Quality of Life Outcomes Using the RAND-36 Questionnaire Before and 1 Year After Bariatric Procedures Comparing Three Groups of Subjects with Different Levels of Activity

	LOW-ACTIVE	MEDIUM-ACTIVE	HIGH-ACTIVE	ALL	p
	MEAN ± SD	MEAN ± SD	MEAN ± SD	MEAN ± SD	p
Preoperative
Physical functioning	59.2 ± 19.1	61.9 ± 18.0	52.6 ± 21.4	56.1 ± 20.2	0.148
Social functioning	67.3 ± 18.1	70.3 ± 25.1	61.7 ± 20.4	65.3 ± 22.9	0.240
Physical role impairment	57.7 ± 38.7	46.6 ± 42.6	35.6 ± 38.6	42.4 ± 40.3	0.175
Emotional role impairment	61.5 ± 42.7	51.7 ± 44.2	54.6 ± 45.8	54.7 ± 44.5	0.807
Mental health	73.5 ± 13.3	73.4 ± 14.0	73.3 ± 13.1	73.3 ± 13.3	0.998
Vitality	50.8 ± 15.1	52.4 ± 19.2	46.6 ± 16.6	49.1 ± 17.3	0.342
Pain	54.5 ± 19.1	60.7 ± 22.9	51.4 ± 23.2	54.8 ± 22.7	0.225
General health perception	41.2 ± 20.6	43.8 ± 18.2	39.8 ± 15.3	41.3 ± 17.0	0.612
Health change	30.8 ± 20.8	32.8 ± 26.8	32.4 ± 22.7	32.3 ± 23.6	0.968
Postoperative
Physical functioning	89.5 ± 18.3	89.5 ± 14.1	88.6 ± 17.7	89.0 ± 16.6	0.850
Social functioning	84.0 ± 21.1	84.9 ± 22.1	81.4 ± 22.9	83.0 ± 22.4	0.316
Physical role impairment	78.5 ± 33.6	77.2 ± 30.0	77.5 ± 30.3	77.5 ± 30.6	0.959
Emotional role impairment	85.6 ± 30.6	84.1 ± 30.8	85.1 ± 28.7	84.8 ± 29.7	0.926
Mental health	77.3 ± 16.4	77.1 ± 18.2	78.6 ± 16.2	77.9 ± 16.9	0.665
Vitality	67.2 ± 20.5	67.5 ± 20.1	67.6 ± 19.7	67.5 ± 19.9	0.985
Pain	84.6 ± 23.1	80.3 ± 26.0	80.7 ± 24.6	81.2 ± 24.8	0.456
General health perception	74.6 ± 21.2	72.1 ± 20.9	73.2 ± 19.7	73.0 ± 20.3	0.695
Health change	64.2 ± 23.8	67.1 ± 26.3	67.6 ± 26.2	67.0 ± 25.9	0.644

Discussion

This study shows that introducing an e-Health platform can be beneficial to improve the standard of care in bariatric surgery programs. Data traffic results show that the e-Health platform reached a large proportion of patients. A significant better weight reduction was seen in the patients who more actively made use of the platform after the operation than patients who did not. However, access to preoperative content did not result in statistically significant differences. Usage of the platform did not result in a difference in quality of life among users.

The platform is designed in such a way that patients get access to new information after the operation. The preoperative content can be seen as preparation for the surgery (e.g., Preparation phase program) and the postoperative content for maintaining weight loss (e.g., Sports program, Weight regain prevention program, Question-of the Week, and more). Data show that there was no difference in weight loss outcomes whether or not patient accessed preoperative content. However, patients who accessed the postoperative content lost statistically significant more weight at 1 and 2 years postoperatively compared with those who did not. Although the difference was small, and questions about clinical relevance remain, the finding suggests that the addition of e-Health might be beneficial especially in the postoperative setting.

An explanation for this could be that patients who are more committed to the cause of losing weight are also more willing to put time and effort in the platform. However, because of the retrospective design of this study, it remains unclear whether added weight loss is due to the increased use of the platform, or if those patients would have lost more weight in the first place.

Literature about the value of e-Health in health care is scarce, probably due to its novelty and different study approaches, also in the bariatric field. This was concluded by a recently published systematic review.⁸ Of the reviewed articles, only one randomized controlled trial (RCT) reported positive effects on weight loss outcomes after bariatric surgery with the addition of e-Health to standard care.¹¹ In this RCT, where 56 patients underwent bariatric surgery and were enrolled for either standard care or received an e-Health solution with a tablet and health app, the e-Health group lost more weight at 1 year postoperatively and maintained this at 2 years postoperatively.¹¹ The results of this study are in line with those findings.

In terms of reach of the provided content a high usage was noted. The proportion of patients who actively used the platform was high with 97% of all patients accessing content on the platform besides the mandatory questionnaire. About 82% connected more than once. Patients visited an average of 51 pages over an average of 12 separate connections per patient in the study period. Many patients commented that they felt that the platform added value to the program and made that they felt better prepared for the surgery and aftercare program. The most accessed content was especially content that was easily accessible. For instance, Preparation phase and Lectures were automatically pushed to the front page of the platform to patients who did not view this content yet. Also, the Videos section was frequently visited. Probably due to patients preferring visual information over written information. Keeping the platform up to date and adjusted to current knowledge is a requirement for it to be an addition to standard care. This can be a time-consuming process. The accessible information needs to be checked regularly by physicians, dieticians, psychologists, obesity nurses, and secretaries. However, this could result in less consultations because patients are better informed. This was not reviewed in this study, however will be assessed in an ongoing randomized controlled trial.¹²

Although unanticipated, the mean age of the population in the most active group was overall higher than in the less active patients. We expected that younger patients would be more active than older patients. An explanation could be that younger patients may already be active on other (social) media platforms or other digital ways to gather information about bariatric surgery and, therefore, put less time in this particular platform. Furthermore, although not statistically significant, the proportion of females was higher in the active groups.

Preoperative health-related quality of life was overall poor and the mean score of all subdomains scored lower than a reference group of healthy Dutch citizen.⁹ Postoperative quality of life improved majorly in all domains. In this study, however, no differences were seen between groups comparing the level of activity on the e-Health platform.

What do the results of the study imply? The finding that specifically postoperative content is associated with better weight reduction might imply that this is a field of opportunity where future e-Health solution need to emphasize on. It was also found that content that was pushed to the front page was viewed more often. It might be beneficial to push personalized content to specific groups (e.g., weight regain prevention program for patients who start to gain weight and sports videos for physical inactive patients). The findings also suggest that there might be several demographical subgroups who are more reachable for e-Health (e.g., age and gender). Future research is needed to identify these groups and determine how they can benefit more of e-Health and how other groups are to be reached. Based on experiences with an e-Health solution in our institution we advise for future solutions to be easy-to-understand and comprehensive for patients and health care professionals.

As mentioned before, the retrospective design is a considerable limitation of this study. These results, therefore, need to be interpreted with caution. Future study, in the form of prospective study designs, is required to establish the true value of e-Health in bariatric surgery.

Conclusion

The introduction of an e-Health platform might be a beneficial addition to standard of care. The content on the platform reached a high percentage of the patients. Patients who were active on the platform postoperatively experienced higher weight loss at 1 and 2 years postoperatively. It might be beneficial for future e-Health solutions to be integrated in a postoperative care program. Quality of life was comparable between groups of different levels of e-Health consumption. Randomized controlled trials are required to further explore the value of e-Health in bariatric surgery.

Footnotes

Acknowledgment

The authors acknowledge the support of the bariatric team on their work on the platform. This material has not been published or submitted for publication elsewhere.

Disclosure Statement

The bariatric department received an educational grant from Medtronic. The authors have no other conflict of interest to report.

Funding Information

No funding was received for this article.

References

Kyrgiou

, Kalliala

, Markozannes

, et al. Adiposity and cancer at major anatomical sites: Umbrella review of the literature. BMJ, 2017; 356:j477.

Avila

, Holloway

, Hahn

, et al. An overview of links between obesity and mental health. Curr Obes Rep, 2015; 4:303–310.

Kivimaki

, Batty

, Singh-Manoux

, et al. Association between common mental disorder and obesity over the adult life course. Br J Psychiatry, 2009; 195:149–155.

Buchwald

, Avidor

, Braunwald

, Jensen

, Pories

, Fahrbach

, Schoelles

. Bariatric surgery: A systematic review and meta-analysis. JAMA, 2004; 292:1724–1737.

Colquitt

, Pickett

, Loveman

, Frampton

. Surgery for weight loss in adults. Cochrane Database Syst Rev, 2014; 8:CD003641.

Raaijmakers

, Pouwels

, Berghuis

, Nienhuijs

. Technology-based interventions in the treatment of overweight and obesity: A systematic review. Appetite, 2015; 95:138–151.

Sorgente

, Pietrabissa

, Manzoni

, et al. Web-based interventions for weight loss or weight loss maintenance in overweight and obese people: A systematic review of systematic reviews. J Med Internet Res, 2017; 19:e229.

Messiah

, Sacher

, Yudkin

, et al. Application and effectiveness of eHealth strategies for metabolic and bariatric surgery patients: A systematic review. Digit Health, 2020; 6:2055207619898987.

van der Zee

, Sanderman

. Measuring the general health status with the RAND-36, a guideline [Het meten van de algemene gezondheidstoestand met de RAND-36, een handleiding], 2nd ed. Groningen: UMCG/Rijksuniversiteit Groningen, Research Institute SHARE, 2012.

10.

Van der Zee

, Sanderman

, Heyink

, de Haes

. Psychometric qualities of the rand 36-item health survey 1.0: A multidimensional measure of general health status. Int J Behav Med, 1996; 3:104–122.

11.

Mangieri

, Johnson

, Sweeney

, et al. Mobile health applications enhance weight loss efficacy following bariatric surgery. Obes Res Clin Pract, 2019; 13:176–179.

12.

Versteegden

DPA

, Van himbeeck

MJJ

, Nienhuijs

. Assessing the value of eHealth for bariatric surgery (BePatient trial): Study protocol for a randomized controlled trial. Trials, 2018; 19:625.