Table 3.

Results of risk of bias assessment.

Appraisal tool for cross-sectional studies (Downes et al., 2016)
Questions	Tahir et al., 2013	Kalafat et al., 2016	Khammash et al., 2005	Mohseni and Mollas, 2018	Kumar et al., 2016	Riccò et al., 2019	Mehmood et al., 2015	Tlemissov et al., 2017	Akman and Kuru al, 2020
Were the aims/objectives of the study clear?	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Was the study design appropriate for the stated aim(s)?	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Was the sample size justified?	No	No	No	No	No	No	No	No	No
Was the target/reference population clearly defined? (Is it clear who the research was about?)	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Was the sample frame taken from an appropriate population base so that it closely represented the target/reference population under investigation?	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Was the selection process likely to select subjects/participants that were representative of the target/reference population under investigation?	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Were measures undertaken to address and categorise non-responders?	No	No	No	No	No	No	No	No	No
Were the risk factor and outcome variables measured appropriate to the aims of the study?	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Were the risk factor and outcome variables measured correctly using instruments/measurements that had been trialled, piloted or published previously?	No	No	No	No	No	Yes	Yes	Yes	Yes
Is it clear what was used to determined statistical significance and/or precision estimates? (e.g. p-values, confidence intervals)	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes
Were the methods (including statistical methods) sufficiently described to enable them to be repeated?	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes
Were the basic data adequately described?	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Does the response rate raise concerns about non-response bias?	Not reported	Not reported	Not reported	Not reported	Not reported	Not reported	Not reported	Not reported	Not reported
If appropriate, was information about non-responders described?	Not reported	Not reported	Not reported	Not reported	Not reported	Not reported	Not reported	Not reported	Not reported
Were the results internally consistent?	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Were the results presented for all the analyses described in the methods?	No	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes
Were the authors' discussions and conclusions justified by the results?	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Were the limitations of the study discussed?	No	Yes	No	Yes	No	Yes	Yes	Yes	Yes
Were there any funding sources or conflicts of interest that may affect the authors' interpretation of the results?	No	No	Not reported	Not reported	Not reported	No	Not reported	No	No
Was ethical approval or consent of participants attained?	Not reported	Not reported	Not reported	Yes	Not reported	Yes	Not reported	Yes	Yes
Risk of bias assessment	High	Some concerns	High	Some concerns	High	Some concerns	Some concerns	Some concerns	Some concerns

Appraisal tool for cross-sectional studies (Downes et al., 2016)							Case series quality appraisal checklist (IHE, 2014)
Questions	Alnasser et al., 2012	Alsofayan et al., 2022	Chamari et al., 2012	Eirale et al., 2013	Sawaya et al., 2021	Shanks et al., 1994	Questions	Kavalci et al., 2013	Aldoais et al., 2020
Were the aims/objectives of the study clear?	Yes	Yes	Yes	Yes	Yes	Yes	Was the hypothesis/aim/objective of the study clearly stated?	Yes	Yes
Was the study design appropriate for the stated aim(s)?	Yes	Yes	Yes	Yes	Yes	Yes	Was the study conducted prospectively?	Yes	Yes
Was the sample size justified?	No	No	No	No	No	No	Were the cases collected in more than one centre?	No	Yes
Was the target/reference population clearly defined? (Is it clear who the research was about?)	Yes	Yes	Yes	Yes	Yes	Yes	Were patients recruited consecutively?	No	No
Was the sample frame taken from an appropriate population base so that it closely represented the target/reference population under investigation?	Yes	Yes	Yes	Yes	Yes	Yes	Were the characteristics of the patients included in the study described?	Yes	Yes
Was the selection process likely to select subjects/participants that were representative of the target/reference population under investigation?	Yes	Yes	Yes	Yes	Yes	Yes	Were the eligibility criteria (i.e., inclusion and exclusion criteria) for entry into the study clearly stated?	Yes	Yes
Were measures undertaken to address and categorise non-responders?	No	No	No	No	No	No	Did patients enter the study at a similar point in the disease?	No	Yes
Were the risk factor and outcome variables measured appropriate to the aims of the study?	Yes	Yes	Yes	Yes	Yes	Yes	Was the intervention of interest clearly described?	Yes	Yes
Were the risk factor and outcome variables measured correctly using instruments/measurements that had been trialled, piloted or published previously?	Yes	Yes	Yes	No	Yes	No	Were additional interventions (co-interventions) clearly described?	No	No
Is it clear what was used to determined statistical significance and/or precision estimates? (e.g. p-values, confidence intervals)	Yes	Yes	Yes	Yes	Yes	No	Were relevant outcome measures established a priori?	Yes	Unclear
Were the methods (including statistical methods) sufficiently described to enable them to be repeated?	Yes	Yes	Yes	Yes	Yes	No	Were outcome assessors blinded to the intervention that patients received?	No	Unclear
Were the basic data adequately described?	Yes	Yes	Yes	Yes	Yes	Yes	Were the relevant outcomes measured using appropriate objective/subjective methods?	No	Yes
Does the response rate raise concerns about non-response bias?	Not reported	Not reported	Not reported	No	Not reported	Not reported	Were the statistical tests used to assess the relevant outcomes appropriate?	Yes	Yes
If appropriate, was information about non-responders described?	Not reported	Not reported	Not reported	No	Not reported	Not reported	Was follow-up long enough for important events and outcomes to occur?	N/A	Yes
Were the results internally consistent?	Yes	Yes	Yes	Yes	Yes	Yes	Were losses to follow-up reported?	N/A	No
Were the results presented for all the analyses described in the methods?	Yes	Yes	Yes	Yes	Yes	No	Did the study provide estimates of random variability in the data analysis of relevant outcomes?	No	No
Were the authors' discussions and conclusions justified by the results?	Yes	Yes	Yes	Yes	Yes	Yes	Were the adverse events reported?	No	No
Were the limitations of the study discussed?	Yes	Yes	No	Yes	Yes	No	Were the conclusions of the study supported by results?	Yes	Yes
Were there any funding sources or conflicts of interest that may affect the authors' interpretation of the results?	No	No	Not reported	No	No	Not reported	Were both competing interests and sources of support for the study reported?	No	No
Was ethical approval or consent of participants attained?	Yes	Yes	Yes	Yes	Yes	Not reported
Risk of bias assessment	Some concerns	Some concerns	High	Some concerns	Some concerns	Some concerns		High	High