Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Bariatric surgery is a type of surgery performed on people who are obese with the purpose of making them lose weight - this includes gastric bypass and gastric banding. It is an increasingly common operation yet the long term benefits and complications are not well known. This study will collect data on every patient in Scotland having weight loss surgery, to monitor their weight, nutrient levels in their blood, whether diabetes gets better or if they develop diabetes in the future, any complications such as wound infections or requiring a second operation, heart attacks, cancer or if they die, and if quality of life improves and they feel more or less anxious or depressed after the surgery. We will follow the patients for 10 years after their surgery.

Who can participate?
Participants will be people undergoing bariatric surgery in Scotland - either in the NHS or private hospitals.

What does the study involve?
The study will follow patients during their normal care before and after surgery. No additional tests will be performed. Results of blood tests and details of any future hospital admissions will be gathered using the data stored in Scottish NHS computer systems. For participants with diabetes, data on their diabetes control, medications and complications will be gathered again from NHS computer systems. Participants will be contacted by post before the operation and annually after the operation to complete a questionnaire on quality of life and also be asked if they have had any complications relate to their surgery. They will be phoned 30 days after surgery to be asked how they are recovering from the surgery.

What are the possible benefits and risks of participating?
There are no benefits or risks to the participants.

Where is the study run from?
The study is run by the University of Glasgow with all NHS and private hospitals providing bariatric surgery in Scotland being involved.

When is the study starting and how long is it expected to run for?
The study will start in January 2012. Participants will be recruited until January 2017 and all participants will be followed up until July 2026.

Who is funding the study?
The National Institute of Health Research Health Technology Appraisal Scheme.

Who is the main contact?
Dr Jennifer Logue

Trial website

Contact information



Primary contact

Dr Jennifer Logue


Contact details

BHF Cardiovascular Research Centre
University of Glasgow
126 University Place
G12 9PP
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number

HTA 10/42/02

Study information

Scientific title

SurgiCal Obesity Treatment Study: a prospective cohort study



Study hypothesis

To establish in a cohort of obese patients who are undergoing bariatric surgery:
1. All cause and cause specific mortality over a mean of 10 years since bariatric surgery.
2. Incidence of cardiovascular disease, cancer and diagnosis of diabetes over a mean of 10 years since bariatric surgery
3. Incidence of acute and chronic postoperative complications. Acute complications, defined as up to three months post surgery, will include surgical site infection; chronic complications will include revisional surgery, plastic surgery and chronic pain.
4. Change in health related quality of life, anxiety and depression over time pre- and post-operatively for a mean of 10 years from date of bariatric surgery.
5. The micronutrient and weight status pre and post-operatively for a mean of 10 years since bariatric surgery.
6. The glycaemic control, lipids, blood pressure, medication prescription, and rate of diabetes complications (microalbuminuria and renal disease, retinopathy and foot ulceration) in those that have pre-existing diabetes or develop diabetes during a mean of 10 years follow up since bariatric surgery.

More details can be found at
Protocol can be found at

Ethics approval

To be submitted to West of Scotland Reserach Ethics Commitee

Study design

Multi-centre prospective cohort study

Primary study design


Secondary study design

Cohort study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet




Bariatric surgery (surgical procedures developed for the primary purpose of weight loss currently laparoscopic gastric banding, sleeve gastrectomy and roux-en-y gastric bypass)

2000 patients undergoing bariatric surgery in the NHS and private sector in Scotland, UK, over a 5-year period will be recruited. The participants will be followed up for a mean of 10 years. The mortality, weight, incident type 2 diabetes mellitus (T2DM), coronary heart disease (CHD), cardiovascular disease (CVD), cancer, fractures, nutritional blood markers, anxiety, depression, post-operative complications, revisional surgery rates, health related quality of life, glycaemic control, diabetic complications and diabetes medications will be recorded.

Intervention type



Not Applicable

Drug names

Primary outcome measure

10-year mortality

Secondary outcome measures

In the 10 years following bariatric surgery:
1. Change in weight / body mass index (BMI) from pre-bariatric surgery weight
2. Rate of incident type 2 diabetes
3. Incidence of fatal and non-fatal coronary heart disease, cardiovascular disease, cancer and fractures
4. Incidence of incidence of nutritional deficiencies
5. Change in incidence of depression and anxiety compared to baseline level pre-operatively
6. Incidence of complications immediately post-operatively and the need for readmission for revisional procedures
7. Change in health-related quality of life compared to baseline level pre-operatively
8. Change in glycaemic control, cardiovascular risk factors, chronic kidney disease (CKD), retinopathy and medications prescribed in patients with diabetes compared to equally obese patient with diabetes who did not have bariatric surgery
9. Cost of the procedure and follow-up (to inform cost-effectiveness analysis)

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Undergoing bariatric surgery in NHS secondary care and private practice in Scotland, UK

Participant type


Age group




Target number of participants


Participant exclusion criteria

Does not meet inclusion criteria

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

BHF Cardiovascular Research Centre
G12 9PP
United Kingdom

Sponsor information


NHS Greater Glasgow and Clyde (UK)

Sponsor details

The Tennent Institute
Western Infirmary
38 Church Street
G11 6NT
United Kingdom

Sponsor type




Funder type


Funder name

NIHR Health Technology Assessment Programme - HTA (UK) (10/42/02)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

(added 22/07/2020)
We intend to publish a further 3 papers:
1. ‘Baseline’ paper providing a profile of the study cohort (‘Health and socio-economic burden in treatment-seeking individuals with severe obesity: profile of the Surgical Obesity Treatment Study (SCOTS) national cohort study’ – this paper was recently submitted to the International Journal of Obesity and is currently under peer-review)
2. A paper reporting complications 1 year post bariatric surgery for the SCOTS cohort - it our intention that this paper will be submitted by the end of 2020
3. A paper outlining complications 3 years post bariatric surgery for the SCOTS cohort – it is our intention that this paper will be submitted by summer 2021

IPD sharing statement:
The current data sharing plans for this study are unknown and will be available at a later date

Intention to publish date


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

2015 protocol in (added 22/07/2020)

Publication citations

Additional files

Editorial Notes

22/07/2020: The following changes were made to the trial record: 1. The publication and dissemination plan was added. 2. The IPD sharing statement was added to the publication and dissemination plan. 3. Publication reference added. 4. The trial website was added. 17/07/2020: The contact email was changed.