Table. National Health and Medical Research Council (NHMRC) body of evidence matrix
|Evidence base||One or more level I studies with a low risk of bias or several level II studies with a low risk of bias
||One or two level II studies with a low risk of bias or a SR/several level III studies with a low risk of bias
||One or two level III studies with a low risk of bias, or level I or II studies with a moderate risk of bias||Level IVstudies, or level I to III studies/SRs with a high risk of bias|
|Consistency||All studies consistent
||Most studies consistent and inconsistency may be explained||Some inconsistency reflecting genuine uncertainty around clinical question||Evidence is inconsistent|
|Clinical impact||Very large||Substantial||Moderate||Slight or restricted|
|Generalisability||Population/s studied in body of evidence are the same as the target population for the guideline||Population/s studied in the body of evidence are similar to the target population for the guideline||Population/s studied in body of evidence differ to target population for guideline but it is clinically sensible to apply this evidence to target population||Population/s studied in body of evidence differ to target population and hard to judge whether it is sensible to generalise to target population|
|Applicability||Directly applicable to Australian healthcare contex||Applicable to Australian healthcare context with few caveats||Probably applicable to Australian healthcare context with some caveats||Not applicable to Australian healthcare context|
SR, systematic review; several, more than two studies.
National Health and Medical Research Council (NHMRC), NHMRC additional levels of evidence and grades for recommendations for developers of guidelines. NHMRC, Canberra, 2009.