There were 95,251 adults that met the eligibility criteria for this study, as shown in Supplementary Figure 1. Overall, the mean (SD) age was 44.2 (11.4) years. The cohort was predominantly female (75.8%). Among eligible patients, 34,240 (35.9%) underwent AGB, 36,206 (38.0%) underwent RYGB, and 24,805 (26.0%) underwent SG. The RYGB group was slightly older (mean: 44.9 vs. 43.7 years for SG, and 43.9 years for AGB) (Table 1), with the highest rates of diabetes (42.4%) and hypertension (70.4%). A total of 1072 deaths occurred during the following and 42,574 patients had 5 years’ follow-up and 51,605 either disenrolled from the health plan or reached the end of the study period (09/30/2015) during the follow-up. The median (interquartile range) follow-up was 3.3 (1.4–5.0) years for AGB, 2.5 (1.0–4.6) years for RYGB, and 1.1 (0.5–2.1) years for SG.
Table 1 Baseline characteristics Figure 1 shows the temporal trend in bariatric surgeries performed from 2006 to 2015. We observed the peak proportions of patients with AGB in 2009 (63.6%) and a substantial decline to 9.1% in 2014. The proportion undergoing SG increased dramatically from 0.8% in 2006 to 62.6% in 2014. The trend for RYGB was relatively stable.
30-Day Composite Outcome
Within 30 days after the index procedure, 3.05% of AGB, 3.80% of RYGB, and 2.78% of SG had the composite outcome (Table 2). Larger proportions required intervention: 2.62% for AGB, 2.14% for RYGB, and 1.71% for SG. The AORs for the composite outcome were significantly lower for AGB relative to RYGB (AOR, 0.81; 95% CI, 0.72–0.92; P<0.001) and SG (AOR, 0.80; 95% CI, 0.73–0.87; P<0.001). Compared to the RYGB group, the SG group had similar probability (AOR, 0.98; 95% CI, 0.88–1.10; P=0.08).
Table 2 Major adverse events occurring in the first 30-days after bariatric surgery, by procedure type Primary Long-Term Outcome
Operation or intervention was more likely following AGB compared to RYGB (AHR, 2.10; 95%CI, 2.00–2.21; P <0.001) but less likely for SG than RYGB (AHR, 0.87; 95%CI, 0.80–0.96; P=.003) (Table 3). Accordingly, the estimated cumulative probability (95% CI) of operation or intervention was higher for AGB, followed by RYGB and then SG. The probability for AGB was 7.0% (6.7–7.3%) at 1 year, 12.6% (12.1–3.1%) at 3 years, and 18.3% (17.6–19.0%) at 5 years (Table 4, Fig. 2a).
Table 3 Adjusted hazard ratios for comparison of different events Table 4 Estimated percentages of patients with outcome event at specified time Heterogeneity of Treatment Effects for Primary Outcome and Subgroup Analysis
Heterogeneity of treatment effects was examined across gender (female, male) and age (<65, ≥65 years) (Table 5). There was no evidence of heterogeneity of treatment effects for SG vs. RYGB for gender and age. However, the increased risk of operation or intervention for AGB, compared to RYGB, was lower for males than females (male: AHR, 1.7; 95%CI, 1.6–1.9; and female: 2.2; 95% CI, 2.1–2.3; P < 0.001), and lower for age ≥65 than age <65 (age ≥65: 1.2; 95%CI, 1.0–1.6; and age <65: 2.2; 95% CI, 2.0–2.3; P < 0.001). Similarly, the increased risk for operation or intervention for AGB, compared to SG, was also lower for males than females and for age ≥65 than age <65 (Table 5). For the subgroup analysis, 91,854 (96.4% of the overall 95,251 patients) aged 20–64 years old, and the results for short- and long-term safety outcomes were similar to the main analysis (Supplementary Table 2).
Table 5 Heterogeneity of treatment effects for operation or intervention outcome by gender and age Secondary Long-Term Outcomes
Endoscopy
Endoscopy for any reason (diagnostic or therapeutic) was less likely for SG vs. RYGB (AHR, 0.43; 95% CI, 0.38–0.48; P < 0.001) and also less likely for AGB vs. RYGB (AHR, 0.36; 95% CI, 0.33–0.39; P < .001) (Table 3). The corresponding cumulative rate of endoscopy (95% CI) was highest for RYGB: 3.7% (3.5–3.8%) at 1 year, 6.0% (5.7–6.3%) at 3 years, and 8.3% (7.9–8.7%) at 5 years (Table 4, Fig. 2c).
Revision
Revisional procedures appeared to be most common after AGB, followed by SG and then RYGB (AHR of AGB vs. RYGB, 11.3; 95% CI, 10.2–12.5; P <0.001; AHR of SG vs. RYGB, 2.9; 95% CI, 2.5–3.3; P <0.001) (Table 3). The highest estimated cumulative probability of revision (95% CI) were on AGB patients: 5.5% (5.2–5.8%) at 1 year, 9.3% (8.8–9.8%) at 3 years, and 14.9% (14.1–15.7%) at 5 years.
Hospitalization
Hospitalization was less likely after ABG and SG than after RYGB: AGB vs. RYGB, AHR=0.73; 95%CI, 0.71–0.76; P <0.001; SG vs. RYGB, AHR=0.79; 95%CI, 0.76–0.83; P <0.001 (Table 3). The estimated cumulative incidence rates of hospitalization (95% CI) for RYGB were 14.3% (14.0–14.7%) at 1 year, 30.0% (29.4–30.6%) at 3 years, and 42.3% (41.5–43.0%) at 5 years (Table 4, Fig. 2d).
Mortality
For time to all-cause mortality, the AHR was significantly lower after SG than RYGB: AHR, 0.76; 95%CI, 0.64–0.92; P =0.004. Compared to RYGB, AGB was associated with lower mortality risk (AHR, 0.49; 95%CI, 0.43–0.56; P =0.001) (Table 3). The estimated cumulative risk of all-cause mortality (95% CI) for RYGB was 0.34% (0.30–0.38%) at 1 year, 0.64% (0.57–0.71%) at 3 years, and 0.98% (0.88–1.09%) at 5 years (Table 4).