Level | Description |
---|---|
I | Systematic review of randomized controlled trials (RCTs) |
II | Article about an RCT |
III | Article about an experimental study without randomization; cohort study; case-control-study |
IV | Article about a non-experimental study (cross-sectional study; case series; case report) |
V | Narrative review or expert opinion (based on clinical experience) without explicit clinical appraisal (e.g., statements, editorials; expert commentaries to published articles; interviews with experts, brief references to NTI-tss in articles; commercial-like reviews) |