Table 3.
Meta-analyses of weight change outcomes: means and 95% confidence intervals are in brackets
| ΔBMI | GB | AGB | SG | Control | Overall | |
|---|---|---|---|---|---|---|
| Year 1 | ||||||
| RCT | Estimates (kg/m2) | −14.53 [−16.82, −12.25] | −10.48 [−13.70, −7.25] | −16.20 [−24.45, −7.95] | -- [--, --] | −13.53 [−15.51, −11.55] |
| # of studies/arms | 9/15 | 3/3 | 1/1 | 0/0 | 12/22 | |
| OBS | Estimates (kg/m2) | −14.32 [−19.02, −9.62] | −7.70 [−9.37, −6.03] | −12.14 [−14.02, −10.26] | −1.01 [−5.26, 3.23] | −11.79 [−13.89, −9.69] |
| # of studies/arms | 27/37 | 24/27 | 17/18 | 3/4 | 57/87 | |
| Year 2 | ||||||
| RCT | Estimates (kg/m2) | −14.47 [−16.98, −11.97] | −11.35 [−14.24, −8.46] | -- [--, --] | -- [--, --] | −13.23 [−15.36, −11.11] |
| # of studies/arms | 6/10 | 2/2 | 0/0 | 0/0 | 8/15 | |
| OBS | Estimates (kg/m2) | −12.93 [−17.39, −8.47] | −8.75 [−10.37, −7.13] | −13.39 [−19.52, −7.26] | 0.10 [−7.39, 7.60] | −11.80 [−13.92, −9.69] |
| # of studies/arms | 12/16 | 14/16 | 5/5 | 1/2 | 29/40 | |
| Year 3 | ||||||
| RCT | Estimates (kg/m2) | -- [--, --] | −9.20 [−15.85, −2.54] | -- [--, --] | -- [--, --] | −9.20 [−15.85, −2.54] |
| # of studies/arms | 0/0 | 1/2 | 0/0 | 0/0 | 1/2 | |
| OBS | Estimates (kg/m2) | −16.78 [−20.57, −12.99] | −11.43 [−18.14, −4.72] | −21.88 [−27.96, −15.79] | -- [--, --] | −15.48 [−18.79, −12.18] |
| # of studies/arms | 6/9 | 7/8 | 2/2 | 0/0 | 17/21 | |
| Year 4 | ||||||
| RCT | Estimates (kg/m2) | -- [--, --] | -- [--, --] | -- [--, --] | -- [--, --] | -- [--, --] |
| # of studies/arms | 0/0 | 0/0 | 0/0 | 0/0 | 0/0 | |
| OBS | Estimates (kg/m2) | −17.86 [−22.20, −13.53] | −6.20 [−18.62, 6.22] | -- [--, --] | -- [--, --] | −17.00 [−20.80, −13.19] |
| # of studies/arms | 5/8 | 1/1 | 0/0 | 0/0 | 8/11 | |
| Year 5 | ||||||
| RCT | Estimates (kg/m2) | -- [--, --] | −11.40 [−28.08, 5.28] | -- [--, --] | -- [--, --] | −11.40 [−28.08, 5.28] |
| # of studies/arms | 0/0 | 1/1 | 0/0 | 0/0 | 1/1 | |
| OBS | Estimates (kg/m2) | −15.96 [−20.52, −11.40] | −12.36 [−16.92, −7.79] | −16.10 [−28.22, −3.98] | -- [--, --] | −14.32 [−17.19, −11.45] |
| # of studies/arms | 4/7 | 4/7 | 1/1 | 0/0 | 10/16 | |
| %EWL | GB | AGB | SG | Control | Overall | |
|---|---|---|---|---|---|---|
| Year 1 | ||||||
| RCT | Estimates (%) | 72.32 [64.60, 80.04] | 33.39 [22.57, 44.21] | 69.70 [41.09, 98.32] | -- [--, --] | 59.82 [50.46, 69.17] |
| # of studies/arms | 5/7 | 4/4 | 1/1 | 0/0 | 9/15 | |
| OBS | Estimates (%) | 63.31 [54.20, 72.43] | 34.26 [33.98, 34.54] | 51.49 [44.41, 58.56] | 20.00 [−25.08,65.08] | 46.16 [43.89, 48.43] |
| # of studies/arms | 17/25 | 14/15 | 11/11 | 1/1 | 39/55 | |
| Year 2 | ||||||
| RCT | Estimates (%) | 74.39 [66.22, 82.55] | 53.58 [32.80, 74.87] | -- [--, --] | -- [--, --] | 70.58 [62.67, 78.50] |
| # of studies/arms | 4/6 | 3/3 | 0/0 | 0/0 | 7/12 | |
| OBS | Estimates (%) | 80.09 [65.74, 94.43] | 52.29 [48.67, 55.92] | 46.72 [42.89, 50.55] | -- [--, --] | 63.98 [55.21, 72.74] |
| # of studies/arms | 7/9 | 11/11 | 3/3 | 0/0 | 22/27 | |
| Year 3 | ||||||
| RCT | Estimates (%) | -- [--, --] | 56.72 [51.59, 61.85] | -- [--, --] | -- [--, --] | 56.72 [51.59, 61.85] |
| # of studies/arms | 0/0 | 2/2 | 0/0 | 0/0 | 2/2 | |
| OBS | Estimates (%) | 76.35 [65.21, 87.50] | 58.30 [42.12, 74.49] | 59.42 [48.05, 70.78] | -- [--, --] | 66.93 [65.05, 68.82] |
| # of studies/arms | 6/8 | 6/6 | 2/2 | 0/0 | 16/19 | |
| Year 4 | ||||||
| RCT | Estimates (%) | -- [--, --] | -- [--, --] | -- [--, --] | -- [--, --] | -- [--, --] |
| # of studies/arms | 0/0 | 0/0 | 0/0 | 0/0 | 0/0 | |
| OBS | Estimates (%) | 76.36 [59.02, 93.70] | 74.91 [58.54, 91.29] | -- [--, --] | -- [--, --] | 74.82 [65.85, 83.80] |
| # of studies/arms | 3/5 | 3/3 | 0/0 | 0/0 | 8/10 | |
| Year 5 | ||||||
| RCT | Estimates (%) | -- [--, --] | 41.60 [−9.75, 92.95] | -- [--, --] | -- [--, --] | 41.60 [−9.75, 92.95] |
| # of studies/arms | 0/0 | 1/1 | 0/0 | 0/0 | 1/1 | |
| OBS | Estimates (%) | 64.92 [44.27, 85.58] | 57.23 [47.23, 67.23] | -- [--, --] | -- [--, --] | 62.24 [58.71, 65.78] |
| # of studies/arms | 3/5 | 5/8 | 0/0 | 0/0 | 10/15 | |
Estimates were obtained from random-effects models using the Frequentist approach. Arms refer to subgroups within studies receiving different surgical procedures. GB: gastric bypass; AGB: adjustable gastric banding; SG: sleeve gastrectomy; Control: non-surgical interventions (non-surgical interventions were included in the analyses only when they were compared with surgical interventions); Overall: all surgery except for Control; RCT: randomized controlled trials; OBS: observational studies; BMI: body mass index; ΔBMI: BMI change; %EWL: percent excess weight loss; --: estimates are not available when 0/0 (no data were included in the analysis) are presented.