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. 2026 Aug 22;30(9):404. doi: 10.1007/s00784-026-07077-2

Table 2.

Risk of bias assessment of the studies included in the present systematic review

Study Study design Assessment tool Quality appraisal details
Caparrotti et al., 2017 Case-control Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★
Lang et al., 2022 Case-control Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★
Renouf et al., 2024 Case-control Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★
Kristensen et al., 2019 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Boromand et al., 2024 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Chopra et al., 2011 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★; Compatibility: ★★; Outcome/Exposure: ★
Dumoulin et al., 2020 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★
Habib et al., 2020 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Khoo et al., 2021 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Koga et al., 2008 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★; Compatibility: ★★; Outcome/Exposure: ★★★
Kojima et al., 2017 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Kovarik et al., 2024 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★; Compatibility: ★★; Outcome/Exposure: ★★★
Lee et al., 2009 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Liao et al., 2020 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Liao et al., 2021 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Liu et al., 2018 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Maesschalck et al., 2016 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Nieward et al., 1996 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Nieward et al., 2014 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Reuther et al., 2002 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Rosenfeld et al., 2021 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Studer et al., 2016 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Zhang et al., 2017 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★★; Compatibility: ★★; Outcome/Exposure: ★★
Liy et al., 2007 Prospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Chen et al., 2005 Retrospective cohort Newcastle–Ottawa Scale (NOS) Selection: ★★★; Compatibility: ★★; Outcome/Exposure: ★★★
Bagan et al., 2009 JBI Critical Appraisal Checklist Inclusion criteria: Yes; Participants detail: Yes; Exposure valid/reliable: Yes; Standardized condition criteria: Yes; Confounders identified: No; Strategies for confounders: No; Results valid/reliable: Yes; Appropriate statistics: Yes
Watson et al., 2023 JBI Critical Appraisal Checklist Inclusion criteria: No; Participants detail: No; Exposure valid/reliable: No; Standardized condition criteria: Yes; Confounders identified: Yes; Strategies for confounders: Yes; Results valid/reliable: Yes; Appropriate statistics: No