Using mean data from the validation study , the trend and directionality in risk was similar in the Roux-en-Y group .
In conclusion , bariatric surgery predicts long-term decreases in CV risk in obese patients
Obese patients have an increased prevalence of  cardiovascular ( CV ) risk factors , which improve with bariatric surgery , but whether bariatric surgery reduces long-term CV events remains ill defined .
Methods for assessing difference between groups in change when initial measurements is subject to intra-individual variation.
Statistical analysis of difference between groups in change for some variable , adjusting for initial value , is complicated by the presence of intra-individual variation in that variable . We estimate here the asymptotic bias that results from calculating the adjusted between-group difference by ordinary least squares ( OLS ) from observed data . We also present explicit formulae that use the OLS estimates , the difference between treatment groups in mean initial values , and a measure of the intra-individual variation to compute a corrected estimator and its variance . Alternatively , we can use OLS on transformed data to obtain unbiased estimates , in which we replace initial observed values by conditional Stein estimates of true values . We illustrate the results with data from an observational study and a clinical trial
Using mean data from the validation study , the trend and directionality in risk was similar in the Roux-en-Y group .
In conclusion , bariatric surgery predicts long-term decreases in CV risk in obese patients
Obese patients have an increased prevalence of  cardiovascular ( CV ) risk factors , which improve with bariatric surgery , but whether bariatric surgery reduces long-term CV events remains ill defined .