Weaver et al developed the STOX (Systematic Reviews, Trials, Observational Studies, Expressions of Opinion) classification of evidence. The authors are from Cardiff University in Wales.
Major Groups:
(1) systematic reviews (S)
(2) trials (T)
(3) observational studies (O)
(4) expressions of opinion (X)
|
Evidence |
STOX |
Level |
|
comprehensive systematic review with >= 1 randomised controlled trial |
S1 |
I |
|
comprehensive systematic review |
S2 |
IV |
|
randomised controlled trial |
T1 |
II |
|
non-randomised controlled trial |
T2 |
III |
|
interventional trial, before and after |
T3 |
III |
|
cohort study |
O1 |
IV |
|
case-control study |
O2 |
IV |
|
cross sectional or longitudinal study |
O3 |
IV |
|
qualitative method only |
O4 |
IV |
|
case study |
O5 |
IV |
|
formal consensus or other professional opinion |
X |
V |
|
literature review without systematic approach |
X |
V |
|
model based on reviews of the literature |
X |
V |
ICD-10: ,
