Table 5.

The AXIAL assessment table below represents the appraisal of all the two cross-sectional studies included

	Wang & Baiorek (2016)	Bonnevie et al. (2004)
Introduction
Were clear aims and objectives of the study used?	Y	Y
Methods
Was the study design appropriate for the stated aim of the study?	Y	Y
Was the sample size justified?	Y	Y
Was the target reference population clearly defined? (Is it clear who the research was about?)	Y	Y
Was the sample frame taken from an appropriate population base so that it closely represented the target reference population under investigation?	N	N
Was the selection process likely to select subjects participants that were representative of the target reference population under investigation?	NA	NA
Were measures undertaken to address and categorise non-responders0	N	Y
Were the risk factor and outcome variables measured appropriate to the aims of the study?	Y	Y
Were the risk factor and outcome variables measured correctly using instruments measurements that had been trialled, piloted or published previously?	Y	Y
Is it clear what was used to determined statistical significance and or precision estimates? (e g. p-values, confidence intervals)	N	Y
Were the methods (including statistical methods) sufficiently described to enable them to be repeated?	N	N
Results
Were the basic data adequately described?	NA	NA
Does the response rate raise concerns about non-response bias?	N	Y
If appropriate, was information about non-responders described?	N	N
Were the results internally consistent?	Y	Y
Were the results presented for all the analyses described in the methods?	Y	Y
Discussion
Were the authors’ discussions and conclusions justified by the results?	Y	Y
Were the limitations of the study discussed?	Y	N
Others
Were there any funding sources or conflicts of interest that may affect the authors’ interpretation of the results?	N	N
Was ethical approval or consent of participants attained?	Y	N