Levels of evidence
| LOE A | Data derived from multiple randomized clinical trials or meta-analyses. |
| LOE B | Data derived from a single randomized clinical trial or large non-randomized studies. |
| LOE C | Consensus of opinion of the experts and/or small studies, retrospective studies, registries. |
LOE, as currently proposed by the European Society of Cardiology and the American Heart Association. The colour coding was used throughout the executive summary and all individual subtopic manuscripts of the ‘Expert Consensus Statements on the Diagnosis and Treatment of Paediatric Pulmonary Hypertension—The European Paediatric Pulmonary Vascular Disease Network’.
LOE, level of evidence.