Five-year attrition, active enrollment, and predictors of level of participation in the Longitudinal Assessment of Bariatric Surgery (LABS-2) study.

BACKGROUND: Reporting high-quality bariatric surgery outcomes depends on participant attrition and level of study participation among enrolled participants. OBJECTIVES: Our aims are to report participant attrition, active enrollment, and level of participation, and to evaluate pre-surgery sociodemographic, physical health, and psychosocial factors as predictors of attrition and level of participation through 5 years. SETTING: The Longitudinal Assessment of Bariatric Surgery-2 study which enrolled 2458 adults undergoing a first bariatric surgical procedure at 1 of 6 US cites from 2006 through 2009. METHODS: In-person research assessments were conducted pre-surgery and annually for five years. Extensive retention strategies including offering remote assessments (telephone, email, mail, or a combination) were fully implemented in 2009. Among living participants, including those inactivated, annual follow-up assessments were categorized as in-person, remote or missed through 5 years. RESULTS: By year 5, 1.7% of participants had died and 3.2% had withdrawn or were inactivated by the study staff; thus, attrition was 4.9% (n = 121). Controlling for site and calendar year, missed assessments increased from 14.7%-21.8% between years 1 and 2 and then stayed relatively stable (20.8%-19.6%) for years 3-5. Younger age, male sex, White race, lower body mass index, smoking, illicit drug use, and higher weight loss expectations preoperatively were independently associated with a higher likelihood of a missed versus in-person assessment across follow-up. CONCLUSION: The LABS-2 participant attrition was low. The percentage of missed assessments did not increase after year 2, perhaps due to implementation of a comprehensive retention plan. Predictors of missed assessments highlight subgroups to target for focused retention efforts.

Postbariatric hypoglycemia: symptom patterns and associated risk factors in the Longitudinal Assessment of Bariatric Surgery study.

BACKGROUND: Postbariatric hypoglycemia (PBH) can be a devastating complication for which current therapies are often incompletely effective. More information is needed regarding frequency, incidence, and risk factors for PBH. OBJECTIVES: To examine hypoglycemia symptoms following Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) and baseline and in-study risk factors. SETTING: Multicenter, at 10 US hospitals in 6 geographically diverse clinical centers. METHODS: A prospective, longitudinal cohort study of adults undergoing RYGB or LAGB as part of clinical care between 2006 and 2009 were recruited and followed until January 31, 2015, with baseline and annual postoperative research assessments. We analyzed baseline prevalence and post-operative incidence and frequency of self-reported hypoglycemia symptoms as well as potential preoperative risk factors. RESULTS: In all groups, postoperative prevalence of hypoglycemia symptoms was 38.5%. Symptom prevalence increased postoperatively from 2.8%-36.4% after RYGB in patients without preoperative diabetes (T2D), with similar patterns in prediabetes (4.9%-29.1%). Individuals with T2D had higher baseline hypoglycemia symptoms (28.9%), increasing after RYGB (57.9%). Hypoglycemia symptoms were lower after LAGB, with 39.1% reported hypoglycemia symptoms at only 1 postoperative visit with few (4.0%) having persistent symptoms at 6 or more annual visits. Timing of symptoms was not restricted to the postprandial state. Symptoms of severe hypoglycemia were reported in 2.6-3.6% after RYGB. The dominant risk factor for postoperative symptoms was preoperative symptoms; additionally, baseline selective serotonin (SSRI) and serotonin-norepinephrine (SNRI) reuptake inhibitor use was also associated with increased risk in multivariable analysis. Weight loss and regain were not related to hypoglycemia symptom reporting. CONCLUSION: Hypoglycemia symptoms increase over time after RYGB, particularly in patients without diabetes. In a small percentage, symptoms can be persistent or severe and require hospitalization. Preoperative hypoglycemia symptoms and SSRI/SNRI use in RYGB patients without diabetes is associated with increased risk of symptoms.

Development and Assessment of a Systematic Approach for Detecting Disparities in Surgical Access.

Importance: Although optimal access is accepted as the key to quality care, an accepted methodology to ascertain potential disparities in surgical access has not been defined. Objective: To develop a systematic approach to detect surgical access disparities. Design, Setting, and Participants: This cross-sectional study used publicly available data from the Health Cost and Utilization Project State Inpatient Database from 2016. Using the surgical rate observed in the 5 highest-ranked counties (HRCs), the expected surgical rate in the 5 lowest-ranked counties (LRCs) in North Carolina were calculated. Patients 18 years and older who underwent an inpatient general surgery procedure and patients who underwent emergency inpatient cholecystectomy, herniorrhaphy, or bariatric surgery in 2016 were included. Data were collected from January to December 2016, and data were analyzed from March to July 2020. Exposures: Health outcome county rank as defined by the Robert Wood Johnson Foundation. Main Outcomes and Measures: The primary outcome was the proportional surgical ratio (PSR), which was the disparity in surgical access defined as the observed number of surgical procedures in the 5 LRCs relative to the expected number of procedures using the 5 HRCs as the standardized reference population. Results: In 2016, approximately 1.9 million adults lived in the 5 HRCs, while approximately 246 854 lived in the 5 LRCs. A total of 28 924 inpatient general surgical procedures were performed, with 4521 being performed in those living in the 5 LRCs and 24 403 in those living in the 5 HRCs. The rate of general surgery in the 5 HRCs was 13.09 procedures per 1000 population. Using the 5 HRCs as the reference, the PSR for the 5 LRCs was 1.40 (95% CI, 1.35-1.44). For emergent/urgent cholecystectomy, the PSR for the 5 LRCs was 2.26 (95% CI, 2.02-2.51), and the PSR for emergent/urgent herniorrhaphy was 1.83 (95% CI, 1.33-2.45). Age-adjusted rate of obesity (body mass index [calculated as weight in kilograms divided by height in meters squared] greater than 30), on average, was 36.6% (SD, 3.4) in the 5 LRCs vs 25.4% (SD, 4.6) in the 5 HRCs (P = .002). The rate of bariatric surgery in the 5 HRCs was 33.07 per 10 000 population with obesity. For the 5 LRCs, the PSR was 0.60 (95% CI, 0.51-0.69). Conclusions and Relevance: The PSR is a systematic approach to define potential disparities in surgical access and should be useful for identifying, investigating, and monitoring interventions intended to mitigate disparities in surgical access that effects the health of vulnerable populations.

Diabetes Remission Status During Seven-year Follow-up of the Longitudinal Assessment of Bariatric Surgery Study.

CONTEXT: Few studies have examined the clinical characteristics that predict durable, long-term diabetes remission after bariatric surgery. OBJECTIVE: To compare diabetes prevalence and remission rates during 7-year follow-up after Roux-en-Y gastric bypass (RYGB) and laparoscopic gastric banding (LAGB). DESIGN: An observational cohort of adults with severe obesity recruited between 2006 and 2009 who completed annual research assessments for up to 7 years after RYGB or LAGB. SETTING: Ten US hospitals. PARTICIPANTS: A total sample of 2256 participants, 827 with known diabetes status at both baseline and at least 1 follow-up visit. INTERVENTIONS: Roux-en-Y gastric bypass or LAGB. MAIN OUTCOME MEASURES: Diabetes rates and associations of patient characteristics with remission status. RESULTS: Diabetes remission occurred in 57% (46% complete, 11% partial) after RYGB and 22.5% (16.9% complete, 5.6% partial) after LAGB. Following both procedures, remission was greater in younger participants and those with shorter diabetes duration, higher C-peptide levels, higher homeostatic model assessment of ß-cell function (HOMA %B), and lower insulin usage at baseline, and with greater postsurgical weight loss. After LAGB, reduced HOMA insulin resistance (IR) was associated with a greater likelihood of diabetes remission, whereas increased HOMA-%B predicted remission after RYGB. Controlling for weight lost, diabetes remission remained nearly 4-fold higher compared with LAGB. CONCLUSIONS: Durable, long-term diabetes remission following bariatric surgery is more likely when performed soon after diagnosis when diabetes medication burden is low and beta-cell function is preserved. A greater weight-independent likelihood of diabetes remission after RYGB than LAGB suggests mechanisms beyond weight loss contribute to improved beta-cell function after RYGB.Trial Registration clinicaltrials.gov Identifier: NCT00465829.

Association between weight loss and serum biomarkers with risk of incident cancer in the Longitudinal Assessment of Bariatric Surgery cohort.

BACKGROUND: Bariatric surgery reduces cancer risk in populations with obesity. It is unclear if weight loss alone or metabolic changes related to bariatric surgery cause this effect. OBJECTIVE: We evaluated the relationship between surgical weight loss and serum biomarker changes with incident cancer in a bariatric surgery cohort. SETTING: Ten U.S. clinical facilities. METHODS: The Longitudinal Assessment of Bariatric Surgery 2 (LABS-2) is a prospective multicenter cohort (n = 2458, 79% female, mean age = 46). We evaluated weight and serum biomarkers, measured preoperatively and 1 year postoperatively, as predictors for incident cancer. Associations were determined using Cox proportional hazards models adjusting for weight loss, age, sex, education, and smoking history. RESULTS: Over 8759 person-years of follow-up, 82 patients reported new cancer diagnosis (936 per 100,000 person-years, 95% confidence interval [CI]: 749-1156). Cancer risk was decreased by approximately 50% in participants with 20% to 34.9% total weight loss (TWL) compared with <20% TWL (hazard ratio [HR] = .49, 95%CI: .29-.83). Reduced cancer risk was observed with percent decrease from baseline for glucose (per 10%, HR = .94, 95%CI: .90-.99), proinsulin (per 20%, HR = .95, 95%CI: .93-.98), insulin (per 30%, HR = .97, 95%CI: .96-.99), and leptin (per 20%, HR = .81, 95%CI: .68-.97), and per 15% percent increase in ghrelin (HR = .94, 95%CI: .29-.83). CONCLUSIONS: After bariatric surgery, cancer risk is reduced >50% when weight loss exceeds 20% TWL compared with patients with <20% TWL. Weight loss alone may not explain the observed risk reduction, as improvements in diabetes, leptin, and ghrelin were associated with decreased cancer risk.

Bariatric Surgery Among Medicare Subgroups: Short- and Long-Term Outcomes.

OBJECTIVE: This study sought to examine weight change, postoperative adverse events, and related outcomes of interest among age-qualified (AQ) and disability-qualified (DQ) Medicare recipients compared with non-Medicare (NM) patients undergoing an initial bariatric procedure. METHODS: The Longitudinal Assessment of Bariatric Surgery (LABS-2) is an observational cohort study of 2,458 adults who underwent Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB) bariatric surgery. Weight, percentage body fat, functional status, and comorbidities, as well as postoperative adverse events, were assessed at baseline and annually for 5 years. The 1,943 participants who reported insurance type were categorized into the following groups: AQ, DQ, or NM. RESULTS: The median preoperative BMI ranged from 45 to 48 kg/m2 across groups. For RYGB, 5-year BMI loss was approximately 30% for all groups, and for LAGB, BMI loss was 12% to 15%. Diabetes remission after 5 years was also similar across groups within procedure types (RYGB: 33%-40%; LAGB: 13%-19%). The frequency of adverse events after RYGB ranged from 4.1% for NM participants to 6.7% for DQ participants. After LAGB, there were no adverse events for the AQ group, whereas 3% of DQ participants and 1.8% of NM participants had at least one adverse event. CONCLUSIONS: Medicare participants experienced substantial BMI loss and diabetes remission, with a frequency of adverse events similar to that of NM participants.

Association of Obesity Subtypes in the Longitudinal Assessment of Bariatric Surgery Study and 3-Year Postoperative Weight Change.

OBJECTIVE: The study objective was to empirically identify subgroups of patients with obesity and investigate their association with postoperative weight change. METHODS: A longitudinal analysis of 2,458 adults in the Longitudinal Assessment of Bariatric Surgery (LABS) study was used. Baseline data were used to identify subgroups. The outcome was 3-year weight change after bariatric surgery. RESULTS: We identified four classes (subtypes) of obesity, which could be characterized as diabetes with low rates of high-density lipoprotein (Class 1), disordered eating (Class 2), mixed (Class 3), and extreme obesity with early onset (Class 4). Approximately 98% of participants in Class 1 had diabetes compared with < 40% in the other classes. There were high rates of binge eating in Class 2, and more than 92% of those in this class reported eating when not hungry. Class 4 was characterized by a higher BMI at baseline. Adults in Class 4 lost an average of 25.0% (males) and 30.3% (females) of their baseline weight over 3 years. In contrast with participants in Class 1, those in Classes 2 and 3 had significantly larger 3-year weight losses than their peers in Class 4. CONCLUSIONS: Obesity is a heterogeneous disease. Bariatric surgery may be most beneficial for adults with disordered eating.

Insurance status differences in weight loss and regain over 5 years following bariatric surgery.

BACKGROUND: The effectiveness of bariatric surgery among Medicaid beneficiaries, a population with a disproportionately high burden of obesity, remains unclear. We sought to determine if weight loss and regain following bariatric surgery differed in Medicaid patients compared to commercial insurance. SUBJECTS/METHODS: Data from the Longitudinal Assessment of Bariatric Surgery, a ten-site observational cohort of adults undergoing bariatric surgery (2006-2009) were examined for patients who underwent Roux-en-Y Gastric Bypass (RYGB), Laparoscopic Adjustable Band (LAGB), or Sleeve Gastrectomy (SG). Using piecewise spline linear mixed-effect models, weight change over 5 years was modeled as a function of insurance type (Medicaid, N = 190; commercially insured, N = 1448), time, procedure type, and sociodemographic characteristics; additionally, interactions between all time, insurance, and procedure type indicators allowed time- and procedure-specific associations with insurance type. For each time-spline, mean (kg) difference in weight change in commercially insured versus Medicaid patients was calculated. RESULTS: Medicaid patients had higher mean weight at baseline (138.3 kg vs. 131.2 kg). From 0 to 1 year post-operatively, Medicaid patients lost similar amounts of weight to commercial patients following all procedure types (mean weight Δ difference [95% CI]: RYGB: -0.9 [-3.2, 1.4]; LAGB: -1.5 [-6.7, 3.8]; SG: 5.1 [-4.0, 14.2]). From 1 to 3 years post-operatively Medicaid and commercial patients continued to experience minimal weight loss or began to slowly regain weight (mean weight Δ difference [95% CI]: RYGB: 0.9 [0.0, 2.0]; LAGB: -2.1 [-4.2, 0.1]; SG: 0.7 [-3.0, 4.3]). From 3 to 5 years post-operatively, the rate of regain tended to be faster among commercial patients compared to Medicaid patients (mean weight Δ difference [95% CI]: RYGB: 1.1 [0.1, 2.0]; LAGB: 1.5 [-0.5, 3.5]; SG: 1.0 [-2.5, 4.5]). CONCLUSIONS: Although Medicaid patients had a higher baseline weight, they achieved similar amounts of weight loss and tended to regain weight at a slower rate than commercial patients.

Seven-Year Weight Trajectories and Health Outcomes in the Longitudinal Assessment of Bariatric Surgery (LABS) Study.

Importance: More information is needed about the durability of weight loss and health improvements after bariatric surgical procedures. Objective: To examine long-term weight change and health status following Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB). Design, Setting, and Participants: The Longitudinal Assessment of Bariatric Surgery (LABS) study is a multicenter observational cohort study at 10 US hospitals in 6 geographically diverse clinical centers. Adults undergoing bariatric surgical procedures as part of clinical care between 2006 and 2009 were recruited and followed up until January 31, 2015. Participants completed presurgery, 6-month, and annual research assessments for up to 7 years. Main Outcome and Measures: Percentage of weight change from baseline, diabetes, dyslipidemia, and hypertension, determined by physical measures, laboratory testing, and medication use. Results: Of 2348 participants, 1738 underwent RYGB (74%) and 610 underwent LAGB (26%). For RYBG, the median age was 45 years (range, 19-75 years), the median body mass index (calculated as weight in kilograms divided by height in meters squared) was 47 (range, 34-81), 1389 participants (80%) were women, and 257 participants (15%) were nonwhite. For LAGB, the median age was 48 years (range, 18-78), the body mass index was 44 (range, 33-87), 465 participants (76%) were women, and 63 participants (10%) were nonwhite. Follow-up weights were obtained in 1300 of 1569 (83%) eligible for a year-7 visit. Seven years following RYGB, mean weight loss was 38.2 kg (95% CI, 36.9-39.5), or 28.4% (95% CI, 27.6-29.2) of baseline weight; between years 3 and 7 mean weight regain was 3.9% (95% CI, 3.4-4.4) of baseline weight. Seven years after LAGB, mean weight loss was 18.8 kg (95% CI, 16.3-21.3) or 14.9% (95% CI, 13.1-16.7), with 1.4% (95% CI, 0.4-2.4) regain. Six distinct weight change trajectory patterns for RYGB and 7 for LAGB were identified. Most participants followed trajectories in which weight regain from 3 to 7 years was small relative to year-3 weight loss, but patterns were variable. Compared with baseline, dyslipidemia prevalence was lower 7 years following both procedures; diabetes and hypertension prevalence were lower following RYGB only. Among those with diabetes at baseline (488 of 1723 with RYGB [28%]; 175 of 604 with LAGB [29%]), the proportion in remission at 1, 3, 5, and 7 years were 71.2% (95% CI, 67.0-75.4), 69.4% (95% CI, 65.0-73.8), 64.6% (95% CI, 60.0-69.2), and 60.2% (95% CI, 54.7-65.6), respectively, for RYGB and 30.7% (95% CI, 22.8-38.7), 29.3% (95% CI, 21.6-37.1), 29.2% (95% CI, 21.0-37.4), and 20.3% (95% CI, 9.7-30.9) for LAGB. The incidence of diabetes at all follow-up assessments was less than 1.5% for RYGB. Bariatric reoperations occurred in 14 RYGB and 160 LAGB participants. Conclusions and Relevance: Following bariatric surgery, different weight loss patterns were observed, but most participants maintained much of their weight loss with variable fluctuations over the long term. There was some decline in diabetes remission over time, but the incidence of new cases is low following RYGB. Trial Registration: clinicaltrials.gov Identifier: NCT00465829.

Type 2 Diabetes Remission Rates After Laparoscopic Gastric Bypass and Gastric Banding: Results of the Longitudinal Assessment of Bariatric Surgery Study.

OBJECTIVE: The goals of this study were to determine baseline and postbariatric surgical characteristics associated with type 2 diabetes remission and if, after controlling for differences in weight loss, diabetes remission was greater after Roux-en-Y gastric bypass (RYGBP) than laparoscopic gastric banding (LAGB). RESEARCH DESIGN AND METHODS: An observational cohort of obese participants was studied using generalized linear mixed models to examine the associations of bariatric surgery type and diabetes remission rates for up to 3 years. Of 2,458 obese participants enrolled, 1,868 (76%) had complete data to assess diabetes status at both baseline and at least one follow-up visit. Of these, 627 participants (34%) were classified with diabetes: 466 underwent RYGBP and 140 underwent LAGB. RESULTS: After 3 years, 68.7% of RYGBP and 30.2% of LAGB participants were in diabetes remission. Baseline factors associated with diabetes remission included a lower weight for LAGB, greater fasting C-peptide, lower leptin-to-fat mass ratio for RYGBP, and a lower hemoglobin A1c without need for insulin for both procedures. After both procedures, greater postsurgical weight loss was associated with remission. However, even after controlling for differences in amount of weight lost, relative diabetes remission rates remained nearly twofold higher after RYGBP than LAGB. CONCLUSIONS: Diabetes remission up to 3 years after RYGBP and LAGB was proportionally higher with increasing postsurgical weight loss. However, the nearly twofold greater weight loss-adjusted likelihood of diabetes remission in subjects undergoing RYGBP than LAGB suggests unique mechanisms contributing to improved glucose metabolism beyond weight loss after RYGBP.

Preoperative factors and 3-year weight change in the Longitudinal Assessment of Bariatric Surgery (LABS) consortium.

BACKGROUND: Limited data guide the prediction of weight loss success or failure after bariatric surgery according to presurgery factors. There is significant variation in weight change after bariatric surgery and much interest in identifying preoperative factors that may contribute to these differences. This report evaluates the associations of a comprehensive set of baseline factors and 3-year weight change. SETTING: Ten hospitals in 6 geographically diverse clinical centers in the United States. METHODS: Adults undergoing a first bariatric surgical procedure as part of clinical care by participating surgeons were recruited between 2006 and 2009. Participants completed research assessments utilizing standardized and detailed data collection on over 100 preoperative and operative parameters for individuals undergoing Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB). Weight was measured 3 years after surgery. Percent weight change for RYGB or LAGB from baseline to 3 years was analyzed as both a continuous and dichotomous outcome with cut points at 25% for RYGB and 10% for LAGB. Multivariable linear and logistic regression models were used to identify independent baseline predictors of the continuous and categorical outcomes, respectively. RESULTS: The median weight loss 3 years after surgery for RYGB (n = 1513) participants was 31.5% (IQR: 24.6%-38.4%; range, 59.2% loss to .9% gain) of baseline weight and 16.0% (IQR: 8.1%-23.1%; range, 56.1% loss to 12.5% gain) for LAGB (n = 509) participants. The median age was 46 years for RYGB and 48 years for LAGB; 80% of RYGB participants and 75% of LAGB participants were female; and the median baseline body mass index (BMI) was 46 kg/m(2) for RYGB and 44 kg/m(2) for LAGB. For RYGB, black participants lost 2.7% less weight compared with whites and participants with diabetes at baseline had 3.7% less weight loss at year 3 than those without diabetes at baseline. There were small but statistically significant differences in weight change for RYGB in those with abnormal kidney function and current or recent smoking. For LAGB participants, those with a large band circumference had 75% greater odds of experiencing less than 10% weight loss after adjusting for BMI and sex. CONCLUSIONS: Few baseline variables were associated with 3-year weight change and the effects were small. These results indicate that baseline variables have limited predictive value for an individual's chance of a successful weight loss outcome after bariatric surgery. TRIAL REGISTRATION: NCT00465829, ClinicalTrials.gov.

The BMI: Is It Time to Scratch for a More Accurate Assessment of Metabolic Dysfunction?

The body mass index (BMI = Kg/M(2)) is not a valid measure for clinical decisions, especially whether a patient will benefit from bariatric surgery. The measure, as used, discriminates against the muscular, the aged, women, and racial groups such as Asians and African Americans. The requirement must be eliminated since it denies many patients the only currently available therapy. This chapter provides the bibliographic data to support this argument and should prove useful in convincing carriers that the BMI is an inaccurate and, too often, cruel guideline.

Mobilization of the obese patient and prevention of injury.

OBJECTIVES AND BACKGROUND: Obese patients are difficult to transport between emergency departments, imaging facilities, operating rooms, intensive care units, acute care units, and rehabilitation facilities. Each move, along with turning, bathing, and access to bathrooms, poses risks of injury to patients and personnel. Similarly, inadequate mobilization raises the risk of pressure ulcers. The costs can be prohibitive. METHODS: On 6 pilot units, mobilization of patients was delegated to trained lift team technicians who covered the units in pairs, 24 hours per day, 7 days per week, to assist with moving and lifting of patients weighing 200 pounds or more, with a Braden Scale score of 18 or less and/or the presence of pressure ulcers. RESULTS: In fiscal year 2012, hospital-acquired pressure ulcers on pilot units decreased by 43% (from 61 to 35). Patient handling-related employee injuries on pilot units decreased by 38.5% (from 13 to 8). Employee satisfaction related to organizational commitment to employee safety and impact on job satisfaction was positively impacted by implementation of the lift team. With the reduction in employee injuries and the fall in the prevalence of pressure ulcers, the adoption of the lift team program decreased costs by $493,293.00. CONCLUSIONS: Implementation of lift teams on pilot nursing units decreased patient handling-related employee injuries, resulting in sharp improvements in quality patient care and reduced costs.

Longitudinal Assessment of Bariatric Surgery (LABS): retention strategy and results at 24 months.

BACKGROUND: Retaining participants in observational longitudinal studies after bariatric surgery is difficult yet critical because the retention rate affects interpretation and generalizability of results. Strategies for keeping participants involved in such studies are not commonly published. The objective of this study was to review LABS retention strategies and present the 24-month retention data. METHODS: The LABS Consortium monitors an observational cohort study of 2458 adults enrolled before bariatric surgery at 10 centers within the United States (LABS-2). To maximize data completeness, the investigators developed retention strategies, including flexible scheduling, a call protocol, reminder letters, abbreviated visit options, honoraria, travel reimbursement, providing research progress reports, laboratory results, newsletters, study website, and retention surveys. Strategies for locating participants included frequent updates of contact information, sending registered letters, and searching medical and public records. RESULTS: At 12 and 24 months, 2426 and 2405 participants remained active, with vital status known for 98.7% and 97.3% and weight obtained for 95.2% and 92.2%, respectively. There were 148 missed visits (6.2%) at 24 months primarily because of inability to contact the participant. Only 15 (0.6%) active participants at 24 months missed all follow-up visits. Although 42 participants could not be located or contacted at 6 months, data were obtained for 23 (54.7%) of them at 12 months, and of the 52 participants who could not be located or contacted at 12 months, data were obtained for 18 (34.6%) at 24 months. CONCLUSION: Longitudinal studies provide the ability to evaluate long-term effects of bariatric surgical procedures. The retention achieved in LABS is superior to that of many published reports but requires extensive effort and resources. This report identifies useful retention strategies. Further research is needed to identify the efficacy and cost-effectiveness of specific retention strategies.

Distribution of 10-year and lifetime predicted risk for cardiovascular disease prior to surgery in the longitudinal assessment of bariatric surgery-2 study.

Primary prevention guidelines recommend calculation of lifetime cardiovascular disease (CVD) predicted risk in patients who may not meet criteria for high short-term (10-year) Adult Treatment Panel III risk for coronary heart disease (CHD). Extreme obesity and bariatric surgery are more common in women who often have low short-term predicted CHD risk. The distribution and correlates of lifetime CVD predicted risk, however, have not yet been evaluated in bariatric surgical candidates. Using established 10-year (Adult Treatment Panel III) CHD and lifetime CVD risk prediction algorithms and presurgery risk factors, participants from the Longitudinal Assessment of Bariatric Surgery-2 study without prevalent CVD (n = 2,070) were stratified into 3 groups: low 10-year (<10%)/low lifetime (<39%) predicted risk, low 10-year (<10%)/high lifetime (≥39%) predicted risk, and high 10-year (≥10%) predicted risk or diagnosed diabetes. Participants were predominantly white (86%) and women (80%) with a median age of 45 years and median body mass index of 45.6 kg/m(2). High 10-year CHD predicted risk was common (36.5%) and associated with diabetes, male gender, and older age, but not with higher body mass index or high-sensitivity C-reactive protein. Most participants (76%) with low 10-year predicted risk had high lifetime CVD predicted risk, which was associated with dyslipidemia and hypertension but not with body mass index, waist circumference, high-density lipoprotein cholesterol, or high-sensitivity C-reactive protein. In conclusion, bariatric surgical candidates without diabetes or existing CVD are likely to have low short-term, but high lifetime CVD predicted risk. Current data support the need for long-term monitoring and treatment of increased CVD risk factors in bariatric surgical patients to maximize lifetime CVD risk decrease (clinical trial registration, Long-term Effects of Bariatric Surgery, indentifier NCT00465829, available at: http://www.clinicaltrials.gov/ct2/results?term=NCT00465829).

Thirty-day mortality after bariatric surgery: independently adjudicated causes of death in the longitudinal assessment of bariatric surgery.

BACKGROUND: Mortality following bariatric surgery is a rare event in contemporary series, making it difficult for any single center to draw meaningful conclusions as to cause of death. Nevertheless, much of the published mortality data come from single-center case series and reviews of administrative databases. These sources tend to produce lower mortality estimates than those obtained from controlled clinical trials. Furthermore, information about the causes of death and how they were determined is not always available. The aim of the present report is to describe in detail all deaths occurring within 30 days of surgery in the Longitudinal Assessment of Bariatric Surgery (LABS). METHODS: LABS is a ten-center observational cohort study of bariatric surgical outcomes. Data were collected prospectively for bariatric surgeries performed between March 2005 and April 2009. All deaths occurring within 30-days of surgery were identified, and cause of death assigned by an independent Adjudication Subcommittee, blinded to operating surgeon and site. RESULTS: Six thousand one hundred eighteen patients underwent primary bariatric surgery. Eighteen deaths (0.3%) occurred within 30-days of surgery. The most common cause of death was sepsis (33% of deaths), followed by cardiac causes (28%), and pulmonary embolism (17%). For one patient cause of death could not be determined despite examination of all available information. CONCLUSIONS: This study confirms the low 30-day mortality rate following bariatric surgery. The recognized complications of anastomotic leak, cardiac events, and pulmonary emboli accounted for the majority of 30-day deaths.

Comparison of 30-day outcomes after non-LapBand primary and revisional bariatric surgical procedures from the Longitudinal Assessment of Bariatric Surgery study.

BACKGROUND: The goals were to compare the morbidity and mortality between primary and revisional bariatric surgery and to identify the clinical predictors of adverse outcomes among patients undergoing revisional surgery in the Longitudinal Assessment of Bariatric Surgery consortium. The study was multi-institutional at university hospitals in the United States. METHODS: Data from the LABS-1 (safety) cohort were analyzed, excluding primary gastric banding patients. A total of 3802 LABS-1 patients were included: 3577 who underwent primary surgery and 225 who underwent revisional surgery. The demographic, clinical, operative, and 30-day outcome data were compared between the 2 groups. A nonlinear mixed effects logit model was used to identify independent risk factors for adverse outcomes (death, deep vein thrombosis, pulmonary embolism, reintubation, reoperation, or discharge after 30 days). RESULTS: Compared with those undergoing revisional surgery, the primary surgery patients were younger (median age 44 versus 49 years, P <.0001) and more likely to be male (20.5% versus 12.7%, P = .006) and heavier (median body mass index 47.3 versus 41.2 kg/m(2), P <.0001) and to have more co-morbidities (P <.0001), including hypertension (56.0% versus 46.0%, P = .0044), diabetes (35.7% versus 20.0%, P <.0001), and sleep apnea (50.3% versus 27.2%, P <.0001). The operative time for the revisional procedures was longer (median 181 versus 135 min, P <.0001) and associated with greater blood loss (median 100 versus <50 mL, P <.0001). Adverse outcomes were more likely after revisional surgery (15.1% versus 5.3%, P <.0001, odds ratio 2.4, 95% confidence interval 1.6-3.6). After adjusting for patient characteristics previously shown to be associated with adverse outcomes, this difference remained statistically significant (odds ratio 2.3, 95% confidence interval 1.5-3.8). The 30-day mortality rate was similar in the 2 groups (.4%). CONCLUSION: Revisional surgery was performed without substantial mortality but with a greater incidence of adverse outcomes than was primary bariatric surgery.

Relationship between surgeon volume and adverse outcomes after RYGB in Longitudinal Assessment of Bariatric Surgery (LABS) study.

BACKGROUND: Bariatric surgery is technically demanding surgery performed on high-risk patients. Previous studies using administrative databases have shown a relationship between surgeon volume and patient outcome after Roux-en-Y gastric bypass (RYGB). We examined the relationship between surgeons' annual RYGB volumes and 30-day patient outcomes at 10 centers within the United States. METHODS: The Longitudinal Assessment of Bariatric Surgery (LABS)-1 is a prospective study examining the 30-day adverse outcomes after bariatric surgery. The outcomes after RYGB were adjusted by procedure type (open versus laparoscopic), functional status, body mass index, history of deep vein thrombosis, pulmonary embolism, and obstructive sleep apnea. The data were examined to determine the nature and strength of the association between surgeon volume and patients' short-term (30-day) adverse outcomes after RYGB. RESULTS: The analysis included 3410 initial RYGB operations performed by 31 surgeons, 15 of whom averaged <50 cases annually. The crude composite adverse outcome (i.e., death, deep vein thrombosis, pulmonary embolism, reintervention or nondischarge at day 30) incidence was 5.2%. After risk adjustment, a greater surgeon RYGB volume was associated with lower composite event rates, with a continuous relationship (i.e., varying cutpoints differentiated the composite event rates), such that for each 10-case/yr increase in volume, the risk of a composite event decreased by 10%. CONCLUSION: In the LABS, the patient's risk of an adverse outcome after RYGB decreased significantly with the increase in surgeon RYGB volume (cases performed annually).