What are the two major levels of evidence for the validity of NANDA-I nursing diagnoses, and what do they represent?

The two major levels are Level 1, which represents the initial stages of diagnosis development that occur before the diagnosis is included in NANDA-I terminology, and Level 2, which refers to the subsequent stages of clinical development and testing after inclusion, with evidence strength depending on the robustness of the studies. Level 1 covers work from submitting a label through adding a definition and diagnostic components, while Level 2 covers conceptual validity, content validity, and clinical validity.

In the NANDA-I framework, evidence levels are organized into two major levels. Level 1 concerns diagnoses presented to the Diagnostic Development Committee for inclusion and represents the initial development process, before a diagnosis becomes part of the terminology. It includes sub-levels: a label only, a label with definition, and diagnostic components with relationships to outcomes and interventions. Level 2 applies after inclusion in the terminology and represents clinical testing stages. It is subdivided into conceptual validity (which includes conceptual, theoretical-causal, and terminological validity), diagnostic content validity (based on expert content analysis), and clinical validity (ranging from qualitative and demographic validity through construct, selective, discriminant, prognostic, and causal validity to generalized validity). The overall evidence level of a diagnosis is higher when stronger research methods, such as high-quality systematic reviews, support it, while weaker methods yield lower evidence levels.