Cohort profile: The Bariatric Experience Long Term (BELONG): a long-term prospective study to understand the psychosocial, environmental, health and behavioural predictors of weight loss and regain in patients who have bariatric surgery

Abstract

PurposeThe Bariatric Experience Long Term (BELONG) prospective study cohort was created to address limitations in the literature regarding the relationship between surgical weight loss and psychosocial, health, behaviour and environmental factors. The BELONG cohort is unique because it contains 70% gastric sleeve and 64% patients with non-white race/ethnicity and was developed with strong stakeholder engagement including patients and providers.ParticipantsThe BELONG cohort study included 1975 patients preparing to have bariatric surgery who completed a baseline survey in a large integrated health system in Southern California. Patients were primarily women (84%), either black or Hispanic (59%), with a body mass index (BMI) of 45.1±7.4 kg/m2, age 43.3±11.5 years old, and 32% had at least one comorbidity.Findings to dateA total of 5552 patients were approached before surgery between February 2016 and May 2017, and 1975 (42%) completed a baseline survey. A total of 1203 (73%) patients completed the year 1 and 1033 (74%) patients completed the year 3 postoperative survey. Of these survey respondents, 1341 at baseline, 999 at year 1, and 951 at year 3 were included in the analyses of all survey and weight outcome data. A total of 803 (60% of eligible patients) had survey data for all time points. Data collected were self-reported constructs to support the proposed theoretical model. Height, weight and BMI were abstracted from the electronic medical record to obtain the main outcomes of the study: weight loss and regain.Future plansWe will collect self-reported constructs and obtain height, weight and BMI from the electronic medical record 5 years after bariatric surgery between April 2022 and January 2023. We will also collect patient experiences using focus groups of 8–12 patients each throughout 2022.

Neighborhood deprivation and residential property values do not affect weight loss at 1 or 3 years after bariatric surgery

“…Participants were enrolled in BELONG, a prospective longitudinal mixed methods cohort study. Details of the cohort have been published elsewhere [29]. Participants were patients preparing to have bariatric surgery within Kaiser Permanente Southern California (KPSC), a large integrated health care system serving 4.7 million members.…”

“…The application of these criteria resulted in 1341 patients available for the study of surgical weight loss. Differences between patients who completed the surveys and those recruited have been published elsewhere [29]. Briefly, compared with those patients who did not complete a baseline survey, patients who completed a survey were more likely to be women, to have BMI of 40 to 49.99 kg/m 2 , to have a mental illness, and to lose weight in the year before surgery and were less likely to have hypertension.…”

“…The baseline survey for the BELONG study was administered by trained interviewers using the Computer‐Aided Telephone Interview or was self‐directed online with a website specially designed for this purpose. All items included in the baseline survey have been described elsewhere [29]. Self‐reported race and ethnicity, sex, income, and education were all obtained from this survey.…”