Gastric bypass has better outcomes than gastric b and procedures for long-term weight loss , type 2 diabetes control and remission , hypertension , and hyperlipidemia .
Insufficient evidence exists regarding long-term outcomes for gastric sleeve resections
IMPORTANCE Bariatric surgery is an accepted treatment for obesity .
Despite extensive literature , few studies report long-term follow-up in cohorts with adequate retention rates .
OBJECTIVE To assess the quality of evidence and treatment effectiveness 2 years after bariatric procedures for weight loss , type 2 diabetes , hypertension , and hyperlipidemia in severely obese adults .
Loss to Follow-Up in Cohort Studies: How Much is Too Much?
Loss to follow-up is problematic in most cohort studies and often leads to bias . Although guidelines suggest acceptable follow-up rates , the authors are unaware of studies that test the validity of these recommendations . The objective of this study was to determine whether the recommended follow-up thresholds of 60–80 % are associated with biased effects in cohort studies . A simulation study was conducted using 1000 computer replications of a cohort of 500 observations . The logistic regression model included a binary exposure and three confounders . Varied correlation structures of the data represented various levels of confounding . Differing levels of loss to follow-up were generated through three mechanisms : missing completely at r and om ( MCAR ) , missing at r and om ( MAR ) and missing not at r and om ( MNAR ) . The authors found no important bias with levels of loss that varied from 5 to 60 % when loss to follow-up was related to MCAR or MAR mechanisms . However , when observations were lost to follow-up based on a MNAR mechanism , the authors found seriously biased estimates of the odds ratios with low levels of loss to follow-up . Loss to follow-up in cohort studies rarely occurs r and omly . Therefore , when planning a cohort study , one should assume that loss to follow-up is MNAR and attempt to achieve the maximum follow-up rate possible
Gastric bypass has better outcomes than gastric b and procedures for long-term weight loss , type 2 diabetes control and remission , hypertension , and hyperlipidemia .
Insufficient evidence exists regarding long-term outcomes for gastric sleeve resections
IMPORTANCE Bariatric surgery is an accepted treatment for obesity .
Despite extensive literature , few studies report long-term follow-up in cohorts with adequate retention rates .
OBJECTIVE To assess the quality of evidence and treatment effectiveness 2 years after bariatric procedures for weight loss , type 2 diabetes , hypertension , and hyperlipidemia in severely obese adults .