Background: Bariatric surgery is a common procedure worldwide for the treatment of severe obesity and associated comorbid conditions but there is a lack of evidence as to medium-term safety and effectiveness outcomes in a United Kingdom setting.
Objective: To establish the clinical outcomes and adverse events of different bariatric surgical procedures, their impact on quality of life and the effect on comorbidities.
Design: Prospective observational cohort study.
Setting: National Health Service secondary care and private practice in Scotland, United Kingdom.
Participants: Adults (age >16 years) undergoing their first bariatric surgery procedure.
Main outcome measures: Change in weight, hospital length of stay, readmission and reoperation rate, mortality, diabetes outcomes (HbA1c, medications), quality of life, anxiety, depression.
Data sources: Patient-reported outcome measures, hospital records, national electronic health records (Scottish Morbidity Record 01, Scottish Care Information Diabetes, National Records Scotland, Prescription Information System).
Results: Between December 2013 and February 2017, 548 eligible patients were approached and 445 participants were enrolled in the study. Of those, 335 had bariatric surgery and 1 withdrew from the study. Mean age was 46.0 (9.2) years, 74.7% were female and the median body mass index was 46.4 (42.4; 52.0) kg/m2. Weight was available for 128 participants at 3 years: mean change was -19.0% (±14.1) from the operation and -24.2% (±12.8) from the start of the preoperative weight-management programme. One hundred and thirty-nine (41.4%) participants were readmitted to hospital in the same or subsequent 35 months post surgery, 18 (5.4% of the operated cohort) had a reoperation or procedure considered to be related to bariatric surgery gastrointestinal complications or revisions. Fewer than five participants (<2%) died during follow-up. HbA1c was available for 93/182 and diabetes medications for 139/182 participants who had type 2 diabetes prior to surgery; HbA1c mean change was -5.72 (±16.71) (p = 0.001) mmol/mol and 65.5% required no diabetes medications (p < 0.001) at 3 years post surgery. Physical quality of life, available for 101/335 participants, improved in the 3 years post surgery, mean change in Rand 12-item Short Form Survey physical component score 8.32 (±8.95) (p < 0.001); however, there was no change in the prevalence of anxiety or depression.
Limitations: Due to low numbers of bariatric surgery procedures in Scotland, recruitment was stopped before achieving the intended 2000 participants and follow-up was reduced from 10 years to 3 years.
Conclusions: Bariatric surgery is a safe and effective treatment for obesity. Patients in Scotland, UK, appear to be older and have higher body mass than international comparators, which may be due to the small number of procedures performed.
Future work: Intervention studies are required to identify the optimal pre- and post surgery pathway to maximise safety and cost-effectiveness.
Study registration: This study is registered as ISRCTN47072588.
Funding details: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 10/42/02) and is published in full in Health Technology Assessment; Vol. 28, No. 7. See the NIHR Funding and Awards website for further award information.
Keywords: BARIATRIC SURGERY; COHORT STUDIES; DIABETES MELLITUS; ELECTRONIC HEALTH RECORDS; PATIENT-REPORTED OUTCOME MEASURES; POSTOPERATIVE COMPLICATIONS; TYPE 2; WEIGHT LOSS.
Bariatric surgery is performed on the stomach and small bowel to help people living with obesity lose weight. Our research study has looked at who is getting bariatric surgery, if they are having problems afterwards, how much weight they lose and if their medical conditions improve. A total of 444 people who were attending bariatric surgery services in Scotland, UK, agreed to take part and 336 had surgery. One hundred and eighty-nine of them completed a questionnaire before their surgery and 85 of them after 3 years, to tell us about how they were feeling physically and mentally. We looked at their computer hospital records to see how long they spent in hospital, any medical problems and changes to diabetes medicines and tests. One in five people taking part did not have surgery after all; they changed their mind or the hospital teams did not think it would be safe or work well for the patient. Those who had surgery lost 19% of their body weight and those with type 2 diabetes needed less or no medication 3 years after the surgery. The effect of physical symptoms on day-to-day activities improved but mental health did not. Compared to other countries, the people taking part were older, heavier and sicker. They spent longer in hospital after surgery and were more likely to be readmitted to hospital. How many appointments they had or what type of health professional they saw before or after surgery did not change these results. We had hoped to have far more people in this study and be able to answer more questions, but not enough people were getting bariatric surgery in Scotland for us to ask them to take part. Further research is needed to find the best ways to care for people living with obesity who would benefit from bariatric surgery.