Validation of a Score for Supplementation Needs of Vitamins, Micronutrients and Proteins After Bariatric Surgery
Conditions: Obesity &Amp; Overweight, Bariatric Surgery, Bariatric Surgery Complication
Sponsor: Hospital Universitari de Bellvitge

VALIDATION OF A SCORE FOR SUPPLEMENTATION NEEDS OF VITAMINS, 
MICRONUTRIENTS AND PROTEINS AFTER BARIATRIC SURGERY (BARSCORE PROJECT) 
PROTOCOL INFORMATION 
Protocol Code: HUB-CIR-BARSCORE 
Version: 2.0 dated July 22, 2024 
Principal Investigator: 
Dr. Javier OSORIO 
Department of General and Digestive Surgery 
Hospital Universitario de Bellvitge 
Carrer de la Feixa Llarga, s/n, 08907-L'Hospitalet de Llobregat, Barcelona, Spain 
Tel.: +34. 93 2607623 
Co-Principal Investigator: 
Dr. Sebastiano BIONDO 
Department of General and Digestive Surgery 
Hospital Universitario de Bellvitge 
Carrer de la Feixa Llarga, s/n, 08907-L'Hospitalet de Llobregat, Barcelona, Spain 
Tel.: +34. 93 2607623 
Other Investigators: 
Dr. Claudio LAZZARA 
Dra. Lucia SOBRINO 
Dr. David MERINO 
Department of General and Digestive Surgery 
Hospital Universitario de Bellvitge 
Carrer de la Feixa Llarga, s/n, 08907-L'Hospitalet de Llobregat, Barcelona, Spain 
Tel.: +34. 93 2607623 
 
 
 
 
 
 
 
 
 

ABSTRACT 
Obesity is currently a pandemic. The treatment of patients affected by obesity is very 
complex and requires the synergy of a multidisciplinary team that addresses the problem 
in its different spheres. Among the available treatment options, surgery remains the 
most effective in the long term. Among surgical techniques, there are different types 
based on different mechanisms. Among them, hypoabsorptive techniques, which are the 
most effective, can lead to malnutrition and vitamin deficiencies, so the creation of a 
standardized score -similar to Clavien-Dindo- could be a simple, reproducible tool with 
sufficient clinical relevance to allow comparison of nutritional outcomes between 
different surgical techniques. 
Hypothesis: The BARSCORE score will allow estimation of supplementation needs for 
vitamins, micronutrients and proteins after bariatric surgery. 
Objectives: To validate a score in bariatric surgery that grades supplementation needs 
by relating them to patient characteristics and the proposed surgical technique. 
Methodology: Observational, longitudinal, multicenter study. The study sample will 
consist of patients who underwent bariatric surgery between January 2015 and 
December 2021 in participating centers. Patients will be divided into three groups based 
on the surgery performed and the score will be applied. Subsequently, surveys will be 
conducted to evaluate the score and cases for applying the score. For statistical analysis, 
Spearman's correlation test will be used to verify the consistency of the score and a two-
way ANOVA analysis to measure its concordance. 
 
 
 
 
 
 
 
 
 
 
 
 

INTRODUCTION 
Morbid obesity is considered the great epidemic of this century. It is the leading cause 
of non-traumatic death in the Western population and is progressively affecting 
developing countries. In the latest epidemiological studies, it is estimated that in Spain 
more than 15% of the population is overweight, and approximately 5% suffer from 
morbid obesity. 
The treatment of morbid obesity is multidisciplinary, ranging from changes in lifestyle 
habits and diet to surgery. Among all available therapeutic options, bariatric surgery is 
the only cost-effective long-term treatment for patients with morbid obesity. It offers 
better results than pharmacological treatments and lifestyle changes. Furthermore, it 
has been shown to reduce and improve comorbidities, improve quality of life, reduce 
the risk of cardiovascular diseases and mortality, and improve quality of life [1-3]. 
There are currently several standardized bariatric surgical techniques. These techniques 
can be restrictive such as vertical gastrectomy (VG), hypoabsorptive such as duodenal 
switch (DS) and single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-
S), or mixed such as gastric bypass (GBP). Their indication will depend on factors such as 
the patient's BMI, metabolic comorbidities, or the surgical team's experience, among 
others. All of them have proven to be safe in experienced teams, with mortality rates 
equal to or less than 0.5% and morbidity less than 10% [4-5]. 
Although postoperative risks are low, they must be considered along with the potential 
benefits of surgery on an individual basis and as accurately as possible in each case. This 
allows the decision to perform surgery to be made consensually with the patient based 
on objective data. 
One of the main risks, especially of mixed and hypoabsorptive techniques, is the risk of 
malnutrition and vitamin deficiencies. This complication is recorded in the literature in a 
heterogeneous and non-comparable manner. Articles documenting levels of nutrients, 
vitamins, and trace elements in blood during follow-up after bariatric surgery are 
complex to assess since data collection is not performed in a standardized way and it is 
not specified whether blood levels are with or without supplementation or the 
supplementation dose received; making them non-uniform and difficult to compare with 
each other. 
A classification based on the therapeutic effort needed to resolve nutritional deficits 
(similar to the concept of the Clavien-Dindo classification for short-term post-surgical 
complications) could have the advantage of simplicity, reproducibility, and sufficient 
clinical relevance to allow comparison between different surgical techniques. This score 
could be evaluated along with efficacy (amount of weight lost and resolution of 
comorbidities) and morbidity (short and long-term complications) to assess the pros and 
cons of each surgical technique for each patient profile [6-8]. 

The bariatric surgery, endocrinology, and nutrition teams from HUB, HCP, and VHG 
hospitals reached consensus on a score for predicting therapeutic effort in 
supplementation after bariatric surgery. The objective of the present study is to 
retrospectively validate its utility and reproducibility in patients operated on for vertical 
gastrectomy, gastric bypass, duodenal switch, and single-anastomosis duodenal switch 
with a minimum of two years of clinical and analytical follow-up. 
 
HYPOTHESIS 
The BARSCORE score will allow estimation of supplementation needs for vitamins, 
micronutrients, and proteins after bariatric surgery. 
The BARSCORE score will be a coherent score, so that more complex surgeries will have 
higher scores in the score with a Spearman correlation test with p <0.05. 
The BARSCORE score will be a score with a high level of concordance since different 
investigators from each center will score the presented cases in the same way, obtaining 
a two-way analysis of variance with p <0.05. 
The BARSCORE score will be an easy-to-apply score since it will obtain a percentage of 
favorable results greater than 70% in the score evaluation survey. 
 
OBJECTIVES 
General Objective 
To validate a score in bariatric surgery that grades supplementation needs by relating 
them to patient characteristics and the proposed surgical technique. 
Specific Objectives 
1. Demonstrate the coherence of the score after comparing different types of 
surgical techniques with different complexity and their obtained score. 
2. Verify concordance through responses obtained by investigators from each 
center in the case survey to apply the score. 
3. Verify ease of application through the percentage of favorable responses 
obtained in the score evaluation survey by participating investigators from each 
center. 
 
 
 

METHODS 
Study Design 
Observational, multicenter, longitudinal study based on the medical records of a cohort 
of patients operated on for primary laparoscopic bariatric and metabolic surgery from 
January 2015 to October 2022, in participating centers. 
Procedure 
1. Patient recruitment: Inclusion of patients in the multicenter online database. 
2. Patient stratification: Division of patients into three groups according to the 
surgery performed (vertical gastrectomy, gastric bypass, and single and double 
anastomosis duodenal switch) and categorization of patients using the 
supplementation needs score. 
3. Determine score coherence: Comparison of score results between different 
groups of surgical techniques based on their complexity using Spearman's 
correlation coefficient. 
4. Verify score concordance (reproducibility): At least two investigators from each 
center will answer the case survey to apply the score. Subsequently, a two-way 
ANOVA analysis will be performed on the case survey after applying a normal 
distribution transformation of the percentage of correct answers. 
5. Verify ease of score application: Response from at least two investigators from 
each center to a survey about the complexity and utility of the score, performing 
a descriptive analysis of the results. 
Study Population 
Target Population: Patients undergoing primary minimally invasive bariatric surgery 
from the population area of all participating centers, between 18 and 65 years of age, in 
the period from January 2015 to July 2022. 
Inclusion Criteria: 
• 
Patients operated on for primary laparoscopic bariatric surgery using vertical 
gastrectomy, gastric bypass, duodenal switch, or single-anastomosis duodenal 
switch (SADI-S) techniques 
• 
Surgery performed between 2015 and 2022 in participating centers 
• 
Minimum 2-year follow-up 
• 
Available 
analytical 
control 
and 
evaluation 
by 
endocrinologist 
and 
dietitian/nutritionist 

Exclusion Criteria: 
• 
Patients operated on for revisional surgery 
• 
Patients with less frequent techniques such as single-anastomosis gastric bypass 
or intestinal bipartition 
• 
Patients operated on via open approach or requiring conversion to open 
approach during surgery 
• 
Patients with loss to follow-up 
Experimental Treatment 
Primary laparoscopic bariatric or metabolic surgery. 
Primary Outcome Measures 
1. Score Coherence (Time Frame: Minimum 2 years post-surgery follow-up)  
o Spearman correlation coefficient between surgical complexity and 
BARSCORE score 
o Success criterion: p <0.05 
2. Score Concordance (Reproducibility) (Time Frame: Single assessment after 
database completion)  
o Two-way ANOVA analysis of responses from different investigators on 
standardized cases 
o Success criterion: p <0.05 
3. Ease of Application (Time Frame: Single assessment after database completion)  
o Percentage of favorable responses in evaluation survey 
o Success criterion: >70% favorable responses 
Secondary Outcome Measures 
• 
Number of patients in each BARSCORE category after laparoscopic bariatric 
surgery 
• 
Distribution of supplementation requirements by surgical technique 
• 
Inter-center variability in score application 
 
 
 

Sample Size Determination 
This is an exploratory study in which the sample size cannot be numerically justified in 
usual terms. Reliable data on the expected magnitude of differences are currently 
unknown, given that homogeneous results regarding the risk of malnutrition and vitamin 
deficiencies are not available in the literature. 
At least 1,200 patients will be included, corresponding to patients from the study period 
(January 2015 to October 2022) at the main investigational center (Bellvitge Hospital). 
This number seems reasonable in an exploratory context, supported by additional 
references with similar sample sizes in this field. 
Statistical Analysis Plan 
Descriptive Statistics: 
• 
Categorical variables: number of cases and percentages 
• 
Continuous variables: mean and standard deviation 
Primary Analysis: 
1. Coherence: Spearman correlation test (significance: p <0.05) 
2. Concordance: Two-way ANOVA assuming normality and homoscedasticity 
(significance: p <0.05) 
3. Ease of application: Descriptive analysis with percentages (target: >70% 
favorable responses) 
Risk Factors: Initial risk factors include sociodemographic data (age, sex, BMI), 
comorbidities, type of bariatric surgery, and surgical complications. 
 
TIMELINE AND WORK PLAN 
• 
Study initiation: October 2024 
• 
Data collection: October 2024 - December 2024 
• 
Database cleaning and statistical analysis: January 2025 - March 2025 
• 
Survey administration: March 2025 - April 2025 
• 
Final report completion: October 2025 
 
 
 

ETHICAL CONSIDERATIONS 
Data Management 
An electronic data collection questionnaire will be designed in REDCap. The data 
collection system will be online via web, with data stored on an IDIBELL server with high 
security measures. Each investigator will have password-protected access limited to their 
center's data. 
Patient Privacy 
Given that this study is based on anonymized medical record information and 
considering the difficulty of contacting patients and the number of patients lost to 
follow-up, written consent will not be requested. 
Patients will be identified by an identification number assigned when entering the 
database, removing medical record numbers and dates of birth. Only an IDIBELL 
statistician and one reference person per center will have access to patient identification 
correlations, governed by GDPR Article 14 and Spanish Organic Law 3/2018. 
Ethics Committee Approval 
Clinical research ethics committee authorization is attached to the protocol. 
 
RESOURCES AND INFRASTRUCTURE 
Resources and infrastructure from each participating hospital will be used for patient 
recruitment according to usual surgical activity. Computer infrastructure will be provided 
by IDIBELL through the online database for data collection and analysis. 
 
EXPECTED BENEFITS 
This study will create and validate a score that allows measuring and quantifying 
supplementation needs after bariatric surgery in a standardized and comparable 
manner, enabling comparison between techniques, surgeons, and centers. 
The BARSCORE will provide objective information to assess pros and cons of each surgical 
technique individually for each patient: 
• 
Pros: Total weight loss percentage (%TWL) and comorbidity resolution 
• 
Cons: Short-term surgical complications (Clavien-Dindo) and long-term 
complications (BARSCORE) 
This will contribute to providing more comprehensive information for shared informed 
consent. 

REFERENCES 
[1] Rubio, Miguel A., et al. Consensus document on bariatric surgery. Rev Esp Obes. 
2004;4(7). 
[2] Grigaites, Alejandro L., et al. Postoperative morbidity and mortality in laparoscopic 
bariatric surgery: experience in 1020 patients. Revista argentina de cirugía. 
2014;106(2):1-10. 
[3] Zhang, Linda, et al. Perioperative risk and complications of revisional bariatric 
surgery compared to primary Roux-en-Y gastric bypass. Surgical endoscopy. 
2015;29(6):1316-1320. 
[4] Goitein D, Raziel A, Szold A et al. Assessment of perioperative complications 
following primary bariatric surgery according to the Clavien-Dindo classification: 
comparison of sleeve gastrectomy and Roux-Y gastric bypass. Surg Endosc. 2015. 
[5] Anderin C, Gustafsson UO, Heijbel N et al. Weight loss before bariatric surgery and 
postoperative complications: data from the Scandinavian Obesity Registry (SOReg). Ann 
Surg. 2015;261:909–91. 
[6] Guilbert L, Joo P, Ortiz C, Sepúlveda E, Alabi F, León A, et al. Safety and efficacy of 
bariatric surgery in Mexico: detailed analysis of 500 surgeries in a high-volume center. 
Revista de Gastroenterología de México. 2019;84:296–302. 
[7] Dindo D, Demaartines N, Clavien PA. Classification of surgical complications: a new 
proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg. 
2004;240(2):205-13. 
[8] Collins GS, Reitsma JB, Altman DG, et al. Transparent reporting of a multivariable 
prediction model for individual prognosis or diagnosis (TRIPOD): the TRIPOD 
statement. Ann Intern Med. 2015;162:55-63. 
 
 
 
 
 
 
 
 
 

PARTICIPATING CENTERS 
Coordinating Center 
Hospital Universitario de Bellvitge 
• 
Dr. Javier Osorio (Principal Investigator) 
• 
Dra. Lucia Sobrino 
• 
Dr. Claudio Lazzara 
• 
Dr. David Merino de Villasante 
• 
Dra. Nuria Vilarrassa (Endocrinology) 
• 
Dr. Sebastián Videla (Clinical Support) 
• 
Dr. Judith Lafuente (Biostatistics - IDIBELL) 
Participating Centers 
1. Hospital Universitari Vall d'Hebrón, Barcelona - Dr. Ramón Vilallonga Puy 
2. Hospital Clínic i Provincial de Barcelona - Dra. Ainitze Ibarzabal 
3. Hospital Universitari Arnau de Vilanova, Lleida - Dra. Maite Santamaría 
4. Consorci Corporació Sanitària Parc Taulí, Sabadell - Dra. Alexis Luna 
5. Hospital Universitari Mútua Terrassa - Dr. Joaquín Rodriguez Santiago 
6. Hospital Universitario del Mar, Barcelona - Dra. Anna Casajoana 
7. Hospital de Reus - Dra. Fátima Sabench 
8. Clínica Universitaria Navarra, Pamplona - Dra. Carlota Tuero Ojanguren 
9. Hospital Universitario de Donostia, San Sebastian - Dr. Amador García Ruiz de 
Gordejuela 
10. Hospital de Sagunto, Valencia - Dr. Andrés Frangi 
11. Hospital Clínico Universitario de Valencia - Dr. Norberto Casinelo 
12. Hospital Fundación Jiménez-Díaz, Madrid - Dr. Eduardo Serrano 
13. Hospital Rey Juan Carlos, Madrid - Dr. Camilo Castejón 
14. Hospital Universitario La Paz, Madrid - Dr. Pablo Priego 
15. Hospital Virgen de la Arrixaca, Murcia - Dra. María Dolores Frutos 
 

APPENDIX A: CASE APPLICATION SURVEY 
Instructions for Investigators 
Please review each clinical case and assign the appropriate BARSCORE grade according 
to the classification system. This survey will be used to assess inter-rater concordance. 
Case 1: 40-year-old man operated on for gastric bypass nine months ago, who during 
follow-up consults the emergency department for nausea and vomiting. He is admitted 
after diagnosis of B1 deficiency and treated with parenteral vitamin B1. 
Correct Answer: GRADE IIIB 
Case 2: Patient operated on for duodenal switch two years ago on oral 
supplementation with calcium, vitamin D and a multivitamin.  
Correct Answer: GRADE I 
Case 3: 32-year-old man operated on for gastric bypass three years ago who only takes 
a multivitamin complex as supplementation.  
Correct Answer: GRADE I 
Case 4: 35-year-old female patient operated on for single-anastomosis duodenal switch 
one year ago who receives intravenous iron supplements, oral vitamin B12 and 
regularly needs oral enteral nutrition due to hypoalbuminemia.  
Correct Answer: GRADE IV 
Case 5: 33-year-old man operated on for single-anastomosis duodenal switch two years 
ago requiring oral supplementation with iron, vitamin D, calcium and folic acid at 
higher doses than those established by the local protocol.  
Correct Answer: GRADE IIB 
Case 6: 62-year-old woman operated on for gastric bypass seven years ago currently 
without supplementation. During the second year she needed intravenous iron 
supplementation.  
Correct Answer: GRADE IIIA 
Case 7: 33-year-old man operated on for duodenal switch two years ago, after good 
initial control with oral supplementation, needs daily oral protein modules.  
Correct Answer: GRADE IV 
 

Case 8: A patient operated on for duodenal switch who during follow-up presents 
uncontrollable diarrhea 5-7 times a day associated with severe malnutrition, so surgical 
reversal is indicated.  
Correct Answer: GRADE V 
Case 9: 66-year-old female patient operated on for gastric bypass five years ago with 
vitamin B12 and D supplementation according to local protocol and iron oral 
supplementation at doses higher than usual.  
Correct Answer: GRADE IIA 
Case 10: 53-year-old man operated on for sleeve gastrectomy one year ago requiring 
calcium oral supplementation at 1200mg/day and high doses of vitamin B12 and D. 
Correct Answer: GRADE IIA 
Case 11: 45-year-old female patient operated on for duodenal switch four years ago, 
currently with oral supplementation according to protocol but during the first year 
needed high-dose vitamin A, calcium and vitamin D supplementation and parenteral 
vitamin K. 
Correct Answer: GRADE IIIA 
Case 12: 38-year-old woman operated on for gastric bypass three years ago. Currently 
supplemented with calcium, vitamin B12 and D orally at usual doses and oral vitamin E 
and zinc.  
Correct Answer: GRADE IIB 
Case 13: Patient operated on for duodenal switch one and a half years ago who 
presents up to three admissions for lower extremity edema and hypoalbuminemia 
requiring placement of nasojejunal tube for enteral nutrition.  
Correct Answer: GRADE V 
Case 14: 29-year-old man operated on for sleeve gastrectomy five years ago who takes 
as supplementation: multivitamin, vitamin B12, calcium and vitamin D according to his 
center's protocol.  
Correct Answer: GRADE I 
 
 
 
 
 

APPENDIX B: EASE OF APPLICATION SURVEY 
Instructions for Investigators 
Please answer the following questions about the BARSCORE classification system based 
on your experience reviewing the cases and the score definition. 
1. How long did it take you to understand the score? 
• 
5–10 minutes 
• 
10–20 minutes 
• 
>20 minutes 
• 
I did not understand it 
2. Do you think the score is simple? 
• 
Yes 
• 
No 
3. Do you think the score is reproducible? 
• 
Yes 
• 
No 
4. Do you think the score is logical? 
• 
Yes 
• 
No 
5. Do you consider that the score could be useful for your patients? 
• 
Yes 
• 
No 
6. Do you think the score will be beneficial from a hospital perspective? 
• 
Yes 
• 
No 
7. Please note positive aspects of the score (optional): 
 
8. Please note negative aspects of the score (optional): 
 

APPENDIX C: BARSCORE CLASSIFICATION SYSTEM 
Score Application Considerations 
• 
Patient categorization requires >2 years follow-up with analytical control and 
evaluation by endocrinologist + dietitian-nutritionist 
• 
Patients are included in a category if they required supplementation at any time 
from the 3rd month post-surgery until present, even if currently not needed 
• 
Supplements administered routinely by hospital protocol without demonstrated 
analytical deficit are excluded from categories >I