Background:
Loss to follow-up after bariatric surgery is common, and the outcomes of patients lost to follow-up are unknown. We assessed whether there were differences in weight loss between patients who had bariatric surgery and were lost to follow-up (no follow-up for ≥2 years since last clinic visit) compared to those who attended the clinic infrequently (≥2 years between appointments) or had regular follow up.
Methods:
A longitudinal follow-up study of participants with severe obesity (mean BMI±SD and range 53.3±11.2 and 35.0–89.2 kg/m2), aged 21-73 (mean 52.2±11.5) years, who underwent bariatric surgery as public patients from 2009-2017. Patients deemed lost to follow-up were contacted and a clinic visit was arranged for measurements. A generalised linear model including fixed and random effects was used to model the changes in weight, BMI and waist circumference over time.
Results:
Of the 134 patients in this study (44 males), 119 had sleeve gastrectomy, 9 gastric banding, 3 mini-gastric bypass and 3 roux-en-y-gastric-bypass. They achieved a mean weight loss±SE of 21.2±0.6 kg at 3 months (n=127), 34.5±1.3 kg at 12 months (n=104), 36.1±1.6 kg at 18 months (n=83), 34.2±1.8 kg at 2 years (n=86), 32.5±2.0 kg at 3 years (n=46), 28.7±2.3 kg at 4 years (n=33), and 26.8±2.6 kg at 5 years (n=23). There were no differences in mean weight, BMI or waist circumference between people who were lost to follow-up or who attended follow-up infrequently or regularly.
Conclusions:
Contrary to expectations, there were no differences in weight loss whether or not patients returned for follow-up after bariatric surgery. One interpretation is that follow-up is unnecessary for long-term weight maintenance post bariatric surgery, but it is also possible that patients who are achieving successful weight loss do not feel the need to return to the clinic for follow-up.