Severe nutritional complications can occur following Roux-en-Y gastric bypass (RYGB). Adherence to follow-up visits can reduce the risk of many bariatric surgery complications, but whether this applies to severe nutritional complications is unknown.

Determine the association between adherence to follow-up visits after RYGB and risk of severe nutritional complications.

Multicenter publicly-funded Ontario Bariatric Network.

Retrospective cohort study of Ontario adults participating in the Ontario Bariatric Registry who underwent RYGB between January 1, 2009, and December 31, 2015. The primary outcome was a severe nutritional complication (hospital admission with malnutrition or nutrient deficiency) occurring 1 year or more after RYGB. The primary exposure was adherence to postoperative follow-up visits, occurring at 3, 6, and 12 months postoperatively, and categorized as perfect (3 visits), partial (1–2 visits), or none. Cox proportional hazards modeling quantified the association between adherence to follow-up visits and the primary outcome using hazard ratios (HR).

In total, 9105 adults (84% female, age 44.7 ± 10.3 yr) met study criteria. Mean preoperative body mass index (BMI) was 48.6 kg/m². First year follow-up attendance was: 51.7% perfect, 31.6% partial, and 16.7% none. Median time in the study was 3.4 years. Severe nutritional complications occurred in 1.1% of patients. Compared with perfect follow-up, patients with no follow-up (HR 3.09, 95% CI 1.74–5.50) and partial follow-up (HR 1.94, 95% CI 1.25–3.03) had an increased risk of severe nutritional complications.

Adherence to follow-up visits during the first year after RYGB is independently associated with reduction in the risk of subsequent severe nutritional complications.