Table 3 Assessment of methodological quality.

Reference	Defined sample*	Representative sample†	Complete follow up‡	Prognosis§	Blinded outcome¶	Statistical adjustment**	Final score
Gabbe et al 20049	Yes	No	Yes	Yes	No	No	3
Arnason et al 200410	No	No	Yes	Yes	No	No	2
Beynnon et al 20015	Yes	No	Yes	Yes	No	Yes	4
Soderman et al 200111	No	No	No	Yes	No	Yes	2
Leanderson et al 199612	No	No	Yes	Yes	No	No	2
Wiesler et al 199613	No	No	Yes	Yes	No	Yes	3
Shambaugh et al 199114	No	No	Yes	Yes	No	Yes	3
Ekstrand and Gillquist 198315	No	Yes	No	Yes	No	No	2
Payne et al 199716	Yes	No	Yes	Yes	No	Yes	4
Tropp et al 19847	No	Yes	No	No	No	No	1
Willems et al 200517	Yes	No	No	Yes	No	No	2
Willems et al 200518	Yes	Yes	No	Yes	No	No	3
McGuine et al 200019	Yes	No	Yes	Yes	No	Yes	4
Pope et al 19986	Yes	Yes	Yes	Yes	No	Yes	5
Baumhauer et al 19954	Yes	No	Yes	Yes	No	No	3
Hopper et al 199520	No	No	No	Yes	No	No	1
Milgrom et al 199121	No	No	No	Yes	No	No	1
Holme et al 199922	No	No	No	Yes	No	No	1
Eiff et al 199423	Yes	Yes	Yes	No	No	No	3
Watson 199924	No	No	Yes	Yes	No	No	2
Twellaar et al 199725	No	No	No	No	No	No	0

A “yes” is only awarded if the criterion is clearly satisfied. A “no” is awarded if the criterion is clearly not satisfied or if it is unclear if the criterion is satisfied.

*Description of source of subjects and inclusion/exclusion criteria.

†Subjects were selected by random selection or were consecutive cases.

‡At least one prognostic outcome was available from at least 80% of the study population at the three month follow up or later.

§Studies provided raw data, percentages, survival rates, or continuous outcomes.

¶Assessor was unaware of at least one prognostic factor, used to predict the prognostic outcome, at the time they measured the prognostic outcome.

**For at least two prognostic factors with the adjustment factor reported.

NA, Study did not evaluate prognostic factors.