Anemia and Related Nutrient Deficiencies after Roux-en-Y Gastric Bypass Surgery

Study characteristics; Proportion of study participants with anemia before and after RYGB surgery; Proportion of study participants with low ferritin/ serum iron/ vitamin B12/ folate level before and after RYGB surgery; Hemoglobin/Hematocrit level among study participants; Ferritin/ serum Iron/ vitamin B12/ folate level among study participants before and after RYGB surgery before and after RYGB surgery; Literature search and study selection; Forest plot for proportion of study participants with anemia before RYGB and 12 months after RYGB; Forest plot for proportion of study participants with (A) ferritin (B) serum iron (C) vitamin B12 and (D) folate deficiencies before RYGB and 12 months after RYGB; Funnel plot comparing log(mean) and s.e. of log(mean) for proportion of study participants with anemia 12 months after RYGB; MEDLINE (via PubMed) search query with ‘All Fields’; Cochrane Library search query with ‘Search All Text’研究特征；研究对象在Roux-en-Y胃旁路术（RYGB）术前及术后贫血发生率；研究对象在RYGB术前及术后血清铁蛋白/血清铁/维生素B12/叶酸水平低下的发生率；研究对象的血红蛋白/血细胞比容水平；研究对象在RYGB术前及术后的血清铁蛋白/血清铁/维生素B12/叶酸水平；文献检索与研究筛选；研究对象在RYGB术前及术后12个月贫血发生率的森林图；研究对象在RYGB术前及术后12个月（A）铁蛋白缺乏、（B）血清铁缺乏、（C）维生素B12缺乏及（D）叶酸缺乏发生率的森林图；针对研究对象RYGB术后12个月贫血发生率，比较对数均值（log(mean)）与对数均值标准误（s.e. of log(mean)）的漏斗图；以“所有字段”为检索范围的MEDLINE（通过PubMed平台）检索策略；以“检索所有文本”为范围的Cochrane图书馆检索策略