Levels of Evidence
General
General
From the Centre for Evidence-Based Medicine, Oxford
Therapy/Prevention/Etiology/Harm: | |
1a: | Systematic reviews (with homogeneity ) of randomized controlled trials |
1a–: | Systematic review of randomized trials displaying worrisome heterogeneity |
1b: | Individual randomized controlled trials (with narrow confidence interval) |
1b–: | Individual randomized controlled trials (with a wide confidence interval) |
1c: | All or none randomized controlled trials |
2a: | Systematic reviews (with homogeneity) of cohort studies |
2a–: | Systematic reviews of cohort studies displaying worrisome heterogeneity |
2b: | Individual cohort study or low quality randomized controlled trials (<80% follow-up) |
2b–: | Individual cohort study or low quality randomized controlled trials (<80% follow-up / wide confidence interval) |
2c: | 'Outcomes' Research; ecological studies |
3a: | Systematic review (with homogeneity) of case-control studies |
3a–: | Systematic review of case-control studies with worrisome heterogeneity |
3b: | Individual case-control study |
4: | Case-series (and poor quality cohort and case-control studies) |
5: | Expert opinion without explicit critical appraisal, or based on physiology, bench research or 'first principles' |
Diagnosis: | |
1a: | Systematic review (with homogeneity) of Level 1 diagnostic studies; or a clinical rule validated on a test set. |
1a–: | Systematic review of Level 1 diagnostic studies displaying worrisome heterogeneity |
1b: | Independent blind comparison of an appropriate spectrum of consecutive patients, all of whom have undergone both the diagnostic test and the reference standard; or a clinical decision rule not validated on a second set of patients |
1c: | Absolute SpPins And SnNouts (An Absolute SpPin is a diagnostic finding whose Specificity is so high that a Positive result rules-in the diagnosis. An Absolute SnNout is a diagnostic finding whose Sensitivity is so high that a Negative result rules-out the diagnosis). |
2a: | Systematic review (with homogeneity) of Level >2 diagnostic studies |
2a–: | Systematic review of Level >2 diagnostic studies displaying worrisome heterogeneity |
2b: | Any of: 1)independent blind or objective comparison; 2)study performed in a set of non-consecutive patients, or confined to a narrow spectrum of study individuals (or both) all of whom have undergone both the diagnostic test and the reference standard; 3) a diagnostic clinical rule not validated in a test set. |
3a: | Systematic review (with homogeneity) of case-control studies |
3a–: | Systematic review of case-control studies displaying worrisome heterogeneity |
4: | Any of: 1)reference standard was unobjective, unblinded or not independent; 2) positive and negative tests were verified using separate reference standards; 3) study was performed in an inappropriate spectrum of patients. |
5: | Expert opinion without explicit critical appraisal, or based on physiology, bench research or 'first principles' |
Prognosis: | |
1a: | Systematic review (with homogeneity) of inception cohort studies; or a clinical rule validated on a test set. |
1a–: | Systematic review of inception cohort studies displaying worrisome heterogeneity |
1b: | Individual inception cohort study with >80% follow-up; or a clinical rule not validated on a second set of patients |
1c: | All or none case-series |
2a: | Systematic review (with homogeneity) of either retrospective cohort studies or untreated control groups in RCTs. |
2a–: | Systematic review of either retrospective cohort studies or untreated control groups in RCTs displaying worrisome heterogeneity |
2b: | Retrospective cohort study or follow-up of untreated control patients in an RCT; or clinical rule not validated in a test set. |
2c: | 'Outcomes' research |
4: | Case-series (and poor quality prognostic cohort studies) |
5: | Expert opinion without explicit critical appraisal, or based on physiology, bench research or 'first principles' |
Citation
Barry, Henry, et al., editors. "Levels of Evidence." EE+ POEM Archive, John Wiley & Sons, 2019. Evidence Central, evidence.unboundmedicine.com/evidence/view/infoPOEMs/426001/all/Levels_of_Evidence.
Levels of Evidence. In: Barry HH, Ebell MHM, Shaughnessy AFA, et al, eds. EE+ POEM Archive. John Wiley & Sons; 2019. https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426001/all/Levels_of_Evidence. Accessed September 16, 2024.
Levels of Evidence. (2019). In Barry, H., Ebell, M. H., Shaughnessy, A. F., & Slawson, D. C. (Eds.), EE+ POEM Archive. John Wiley & Sons. https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426001/all/Levels_of_Evidence
Levels of Evidence [Internet]. In: Barry HH, Ebell MHM, Shaughnessy AFA, Slawson DCD, editors. EE+ POEM Archive. John Wiley & Sons; 2019. [cited 2024 September 16]. Available from: https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426001/all/Levels_of_Evidence.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC
T1 - Levels of Evidence
ID - 426001
ED - Barry,Henry,
ED - Ebell,Mark H,
ED - Shaughnessy,Allen F,
ED - Slawson,David C,
BT - EE+ POEM Archive
UR - https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426001/all/Levels_of_Evidence
PB - John Wiley & Sons
DB - Evidence Central
DP - Unbound Medicine
ER -