ESO
Evidence classification
| Scheme for a diagnostic measure | Scheme for a therapeutic intervention | |
|---|---|---|
| Class I | A prospective study in a broad spectrum of persons with the suspected condition, using a "gold standard" for case definition, where the test is applied in a blinded evaluation, and enabling the assessment of appropriate tests of diagnostic accuracy | An adequately powered, prospective, randomised, controlled clinical trial with masked outcome assessment in a representative population or an
adequately powered systematic review of prospective randomised controlled clinical trials with masked outcome assessment in representative populations. The following are required: randomisation concealment primary outcome(s) is/are clearly defined exclusion/inclusion criteria are clearly defined adequate accounting for dropouts and crossovers with numbers sufficiently low to have a minimal potential for bias; and relevant baseline characteristics are presented and substantially equivalent among treatment groups or there is appropriate statistical adjustment for differencess |
| Class II | A prospective study of a narrow spectrum of persons with the suspected condition, or a well-designed retrospective study of a broad spectrum of persons with an established condition (by 'gold standard') compared to a broad spectrum of controls, where test is applied in a blinded evaluation, and enabling the assessment of appropriate tests of diagnostic accuracy | Prospective matched-group cohort study in a representative population with masked outcome assessment that meets a-e above or a randomised, controlled trial in a representative population that lacks one criterion a-e |
| Class III | Evidence provided by a retrospective study where either persons with the established condition or controls are of a narrow spectrum, and where test is applied in a blinded evaluation | All other controlled trials (including well-defined natural history controls or patients serving as own controls) in a representative population, where outcome assessment is independent of patient treatment |
| Class IV | Evidence from uncontrolled studies, case series, case reports, or expert opinion | Evidence from uncontrolled studies, case series, case reports, or expert opinion |
