Prevalence of anemia after Roux-en-Y gastric bypass surgery: what is the right number?

Background: The reported prevalence of anemia after malabsorptive bariatric surgery has varied from 5% to 64% in the post-Roux-en-Y gastric bypass (RYGB) population, owing to the small study sample sizes and generally poor follow-up in surgical referral practices. The present study estimated the prevalence of anemia in the post-RYGB population and determined whether an integrated healthcare system with a shared electronic medical record could improve postoperative follow-up.

Methods: The medical records from 1009 sequential patients who had undergone RYGB from 2000 to 2005 were retrospectively analyzed. All anemia data within the healthcare system's electronic medical record were accessible.

Results: Of the 1009 medical records, 720 contained ≥1 year of follow-up data concerning anemia. Anemia had developed or worsened in 259 patients, for a prevalence of 36% in the present sample. The anemia was moderate to severe (hemoglobin <10 g/dL) in 88 patients (12.2%.), many of whom subsequently required parenteral iron. Of the 1009 patients, the follow-up data for ≥3 years concerning anemia were available for only 357 patients (35.4%).

Conclusion: The results of the present study have shown that in a large population of patients undergoing RYGB, the prevalence of anemia was great enough to justify more intensive long-term screening. We hope the findings from the present report influence the national screening standards for this patient population.