Table 1

Critical appraisal of studies

	Item	Study (first author and year)
	Item	Perera, 201922	Finch, 199820	Walker, 201019	King, 201817	Upadhyay, 200018	Forward, 198821	Overall % of yes
	Likelihood of bias*	Low	Low	Low	Unclear	Unclear	High	Overall % of yes
1	Were the study aims and design described adequately and are they compatible?	Yes	Yes	Yes	Yes	Yes	Partial	83
2	Was the study setting, subjects, source, target population and size described adequately?	Yes	Yes	Yes	Yes	Partial	Partial	67
3	Was the method of data collection described adequately and did it seek to minimise information bias?	Yes	Yes	Yes	Partial	Yes	Partial	67
4	Has there been appropriate reporting of attrition of subjects or missing data?	Yes	Partial	Partial	Partial	Partial	Partial	17
5	Was there an injury definition and/or injury severity measure/definition provided and were they suitable for the study design?	Yes	Partial	Yes	Yes	Yes	Partial	67
6	Were the injury outcomes and exposure measures reported in a standardised, justified and reasonable manner?	Partial	Yes	Yes	Yes	Yes	Yes	83
7	Were limitations to the study discussed adequately?	Yes	Yes	Yes	Yes	No	No	67
8	Is there a summary of key results, their potential generalisability and whether they and any conclusions match the aims and/or reflect the limitations of the study?	Yes	Yes	Yes	Yes	Yes	Partial	83
9	Does the study explain any ethics requirements, author conflicts of interest and/or funding arrangements?	Yes	Partial	Yes	Yes	No	No	50