Table 3. Quality assessment of studies using the Newcastle-Ottawa Scale (NOS).
AHRQ: Agency for Healthcare Research and Quality
| Study name | Study type | Selection | Comparability | Exposure | Total score | AHRQ standards |
| Bouchard et al., 2022 [13] | Cohort | 3 | 2 | 3 | 8 | Good quality |
| Carlsson et al., 2020 [14] | Cohort | 3 | 2 | 3 | 8 | Good quality |
| Fisher et al., 2018 [16] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Alkharaiji et al., 2019 [17] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Aminian et al., 2019 [18] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Singh et al., 2020 [19] | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Ardissino et al., 2021 [20] | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Rassen et al., 2021 [21] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Sampalis et al., 2006 [22] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Sjöström et al., 2007 [23] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Romeo et al., 2012 [24] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Sjöström et al., 2012 [25] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Johnson et al., 2013 [26] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Douglas et al., 2015 [27] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Eliasson et al., 2015 [28] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Benotti et al., 2017 [29] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Brown et al., 2020 [30] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Michaels et al., 2020 [31] | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Moussa et al., 2020 [32] | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Stenberg et al., 2020 [33] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Wong et al., 2021 [34] | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Höskuldsdóttir et al., 2020 [35] | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Dash et al., 2021 [36] | Cohort | 2 | 2 | 3 | 7 | Good quality |
| Hung et al., 2021 [37] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Lundberg et al., 2021 [38] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Yuan et al., 2021 [39] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Mentias et al., 2022 [40] | Cohort | 3 | 2 | 3 | 8 | Good quality |
| Persson et al., 2017 [41] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Sundström et al., 2017 [42] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Jamaly et al., 2019 [43] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Liakopoulos et al., 2020 [44] | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Höskuldsdóttir et al., 2021 [45] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Jamaly et al., 2016 [46] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Lynch et al., 2019 [47] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Moussa et al., 2021 [48] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Macdonald Jr et al., 1997 [49] | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Christou et al., 2004 [50] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Batsis et al., 2007 [51] | Cohort | 3 | 2 | 3 | 8 | Good quality |
| Adams et al., 2007 [52] | Cohort | 3 | 2 | 3 | 8 | Good quality |
| Davidson et al., 2016 [54] | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Lent et al., 2017 [55] | Cohort | 4 | 2 | 3 | 9 | Good quality |
| Pontiroli et al., 2018 [56] | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Kauppila et al., 2019 [57] | Cohort | 3 | 2 | 3 | 8 | Good quality |
| Doumouras et al., 2020 [58] (RYGB) | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Doumouras et al., 2020 [58] (SG) | Cohort | 4 | 2 | 2 | 8 | Good quality |
| Sheetz et al., 2020 [59] | Cohort | 3 | 2 | 3 | 8 | Good quality |
| Courcoulas et al., 2021 [60] (RYGB) | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Courcoulas et al., 2021 [60] (SG) | Cohort | 3 | 2 | 2 | 7 | Good quality |
| Doumouras et al., 2021 [61] | Cohort | 4 | 2 | 3 | 9 | Good quality |