UTS Library

Evidence-based Practice & PICO searching: Evidence levels

In this guide:

 

 

Track down evidence from high level to low level

 

NHMRC Body of evidence matrix

Component A B C D
  Excellent Good  Satisfactory Poor
Evidence Base1 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 IV studies, or level I to III studies/SRs with a high risk of bias
Consistency2 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 population3 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 context 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

1 Level of evidence determined from the NHMRC evidence hierarchy – Table 3, Part B

2 If there is only one study, rank this component as ‘not applicable’.

3 For example, results in adults that are clinically sensible to apply to children OR psychosocial outcomes for one cancer that may be applicable to patients with another cancer

Source: NHMRC, p. 7