After publication of our systematic review, one of the included studies (Ruiz‐Tovar, Jaime et al. “Long‐term follow‐up after sleeve gastrectomy versus Roux‐en‐Y gastric bypass versus one‐anastomosis gastric bypass: a prospective randomized comparative study of weight loss and remission of comorbidities.” Surgical endoscopy vol. 33,2 (2019): 401–410) has been retracted (Ruiz‐Tovar, Jaime et al. “Retraction Note to: Long‐term follow‐up after sleeve gastrectomy versus Roux‐en‐Y gastric bypass versus one‐anastomosis gastric bypass: a prospective randomized comparative study of weight loss and remission of comorbidities.” Surgical endoscopy vol. 35,3 (2021): 1492).
In our systematic review, we did raise several concerns regarding the publication by Ruiz‐Tovar et al.: The study was registered in a clinical trial registry only 2 weeks prior to publication of the results, and the authors presented limited data on baseline characteristics and patient selection. Without the exact details on how the study was conducted, we found it difficult to assess potential biases. The study had a relatively large sample size and was heavily weighted (38.8%) in our meta‐analyses, and consequently we performed sensitivity analyses excluding this study. The total effect estimate when comparing the effects of Roux‐en‐Y gastric bypass to sleeve gastrectomy on remission of type 2 diabetes at 1 year changed from [RR (95% CI)] 1.20 (1.00, 1.45), p = 0.047 to 1.33 (1.09, 1.64), p = 0.0056 when this study was excluded. For long‐term follow‐up (2–5 years) we performed a sensitivity analysis excluding the study by Ruiz‐Tovar et al. together with two other studies having high risk of bias in at least three domains (Yang et al. and Tang et al.). The total effect estimate for long term follow‐up, excluding only the study by Ruiz Tovar et al., is 1.08 (0.88, 1.32), p = 0.48, and this estimate was not presented in our systematic review (Figure 1).
FIGURE 1.
Comparing the effects of RYGB and sleeve on remission of T2DM at 2–5 years