What happens to patients who do not follow-up after bariatric surgery?

Loss of follow-up is a concern when tracking long-term clinical outcomes after bariatric surgery. The results of patients who are "lost to follow-up" are not known. After bariatric surgery, the lack of follow-up may result in less weight loss for patients. This study investigated the hypothesis that there are differences between patients who do not automatically return for their annual follow-up and those that do return. Patients who were greater than 14 months postoperative after laparoscopic gastric bypass were contacted if they had not returned for their annual appointment. They were seen in clinic and/or a phone interview was performed for follow-up. These patients (Group A) were compared with patients who returned to see us for their annual appointment (Group B) without us having to notify them. There were 105 consecutive patients, with 48 patients who did not automatically return for their annual appointment. Only six of these patients could not ultimately be contacted. There was no difference in preoperative body mass index between the two groups. Percentage excess body weight loss was greater in Group B (76 vs. 65%; P < 0.003). More patients had successful weight loss (defined as within 50% of ideal body weight) in Group B (50 [88%] vs. 28 [67%]; P < 0.02). We found that a significant number of patients will not comply with regular follow-up care after laparoscopic gastric bypass unless they are prompted to do so by their bariatric clinic. These patients have worse clinical outcome (i.e., less weight loss). Caution should be taken when examining the results of any bariatric study where there is a significant loss to follow-up.