Efficacy of a Mobile Application to Help in Weight Loss Before Bariatric Surgery (VAMOS)

Randomized Clinical Trial to Assess the Efficacy of a Mobile Application to Help in Weight Loss Before Bariatric Surgery: the VAMOS Project (Virtual Accompaniment for Morbid Obesity Surgery)

The present randomized clinical trial aims to prove the safety and efficacy of an interactive mobile application (Care4Today®) to obtain sufficient weight loss and empower patients with morbid obesity before being submitted to a gastric by-pass.

Study Overview

• Status: Completed
• Conditions: Weight Loss; Morbid Obesity
• Intervention / Treatment: Behavioral: Care4Today APP: multimodal digital prehabilitation programme for candidates undergoing bariatric surgery.; Behavioral: Very low calory diet

Detailed Description

Morbid obesity is considered the great epidemic of our century. It is regarded as the first non-traumatic cause of death in the western population and it is also progressively beginning to affect developing countries. The latest epidemiological studies estimate that in Spain more than 15% of the population has overweight and about 5% has morbid obesity.

Obesity treatment is multidisciplinary, from lifestyle and dietary changes to surgery. Amongst the different available treatments, bariatric surgery is the only cost-effective in patients with morbid obesity. Bariatric surgery provides better results compared to both pharmacological treatments (which are less available and less effective) and lifestyle changes. Furthermore, as well as weight loss, it guarantees a better control of comorbidities, reducing the risk of cardiovascular disease, morbidity and mortality, improving quality of life.

Although surgery is the best treatment option, patient commitment is necessary to achieve satisfactory results. Obtaining patient's comprehension of the importance of healthy lifestyle and equilibrated diet alongside with surgical information is generally difficult. Patient's concern needs to be constantly stressed out. The ongoing protocols that include preoperative meetings with surgeons, endocrinologists and nutritionists have been proved as insufficient, especially during the Covid-19 pandemic, when presential visits were reduced or cancelled.

Preoperative optimization with a healthy lifestyle and a balanced diet few months before surgery potentially reduce intraoperative complications alongside with postoperative morbidity and mortality. Level of physical activity, diet and psychological stability could affect surgery's outcome for example reducing liver volume (up to 20%) and mesenteric fat. Also, an improvement in patient's preoperative satisfaction, anxiety and commitment to surgery have been suggested. Their impact on postoperative outcomes is unclear. There is lack of consensus on a standardized preoperative approach and goals. Many health care professionals worldwide strongly believe that preoperative optimization has an important impact on postoperative outcomes, but the evidence supporting this belief is mixed and most often retrospective. Although a positive relationship between self-monitoring behaviors (such as daily food intake diaries and regular self-weighing) and weight loss has been proved, additional instruction and behavioral intervention are needed. Besides weight loss, other factors such as adherence to self-monitoring of weight, recording food intake, increased physical activity could influence postoperative outcomes.

Even though official guidelines for an enhanced recovery (ERAS, Enhanced Recovery After Surgery) in bariatric surgery recommend patient information, education, counseling and preoperative weight loss, the efficacy of these measures has not been proved.

Technological development is an important resource that could help improving communications between patients and health care professionals. Nowadays, the use of a smartphone is widely integrated in daily life of most people. The number of smartphones used is constantly increasing every year. In 2016, there were more than seven billion users worldwide. The worldwide fast widespread of mobile technology in the last 15 years led to an expansion of the applications (APP) market. To date, the biggest APP market are 'Google Play' (Android), 'App store' (Apple) and 'Blackberry World' (Blackberry).

This technological revolution has progressively affected the health world. An increasing number of medical APP have been designed in the last years, few directly managed from health care providers from public or private centers. The Mobile Health APP could led to a simpler, real-time connection between patients and health care professionals alongside with a bidirectional data flow and a steadily monitorization of patients' evolution that could obtain a better preoperative follow-up without increasing the costs.

The present randomized clinical trial aims to prove the safety and efficacy of an interactive mobile application (Care4Today®) to obtain sufficient weight loss and empower patients with morbid obesity before being submitted to a gastric by-pass.

• Study Type: Interventional
• Enrollment (Actual): 142
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Barcelona
    • L'Hospitalet de Llobregat, Barcelona, Spain, 08907
      • Hospital Universitari de Bellvitge

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 61 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients older than 18 and younger than 65 years who meet criteria to undergo bariatric surgery

BMI between 35 and 50 kg/m2 and indication of one-time surgery

Signing the informed consent of the study

Patient suitable for laparoscopic surgery

Patient who demonstrates accessibility to a smartphone and basic digital competence

Exclusion Criteria:

• Previous bariatric surgery

Two-step surgery

Patient without resources to access the use of a Smartphone or without basic digital competence

Contraindication for surgery

Other surgical procedures associated with the same intervention

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: APP group; Four months before surgery, the C4T APP, in addition to standard protocol, will be provided to all the patients randomized in the APP group.	Behavioral: Care4Today APP: multimodal digital prehabilitation programme for candidates undergoing bariatric surgery.; Multimodal digital prehabilitation programme for candidates undergoing bariatric surgery.; Behavioral: Very low calory diet; Standard follow-up with very-low calory diet
Active Comparator: Normal VLCD (Very Low Calory Diet) group; Normal preoperative standard protocol will be provided to all the patients randomized in the normal group.	Behavioral: Very low calory diet; Standard follow-up with very-low calory diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Preoperative weight loss	To compare patients' preoperative weight loss after using the C4T APP versus the standard preoperative protocol.	App will be provided four months before surgery and then preoperative weight loss achieved will be evaluated the day of surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
patient information using the APP	A validated questionnaire will be used to compare patients' information using the APP vs. standard protocol. (10 questions, 1 point each: >6 good information achieved).	App will be provided four months before surgery and patients' information/satisfaction using the APP will be evaluated the day of surgery
patient satisfaction using the APP	A validated questionnaire (will be used to compare patients' satisfaction using the APP vs. standard protocol. (10 items to evaluate as very poor, poor, correct, good, excellent).	App will be provided four months before surgery and patients' information/satisfaction using the APP will be evaluated the day of surgery
Correlation between preoperative weight loss and early complications	Compare complications in the immediate postoperative period (30- and 90-days post-intervention) after the preoperative use of APP vs. standard protocol. Complications will be recorded in our prospective database.	Early complication rate in each group will be evaluated and compared 30 and 90 days postoperative
Correlation between preoperative weight loss and Early postoperative weight loss	Compare patients' weight loss 3 months after surgery using the APP vs. standard protocol	Patients' weight loss in each group will be evaluated and compared 3 months after surgery

Collaborators and Investigators

• Sponsor: Hospital Universitari de Bellvitge

Study record dates

Study Major Dates

• Study Start (Actual): October 18, 2022
• Primary Completion (Actual): November 1, 2023
• Study Completion (Actual): November 1, 2023

Study Registration Dates

• First Submitted: September 23, 2022
• First Submitted That Met QC Criteria: October 26, 2022
• First Posted (Actual): October 28, 2022

Study Record Updates

• Last Update Posted (Actual): March 10, 2026
• Last Update Submitted That Met QC Criteria: March 7, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Obesity; Mobile APP; R-en-Y gastric bypass; Preoperative weight loss
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Body Weight Changes; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Weight Loss; Obesity, Morbid
• Other Study ID Numbers: HUB-VAMOS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No