What is evidence-based nursing?

Evidence-based nursing (EBN) is integration of the best available evidence, nursing expertise, patient preferences and resources (Figure 1). The aim of EBN is ensuring that patients receive high quality nursing care. EBN is a foundation for nurse’s critical thinking and decision-making. In EBN PICO(T) format (Table 1) is often used to frame a research question. Framing the question helps brake down the clinical question into smaller parts and identify keywords and therefore to find best available evidence. Best evidence available consists of research evidence, evaluated based on the same levels of evidence as in medicine. Levels of evidence are arranged in a ranking system to describe the strength of the research study. Careful reading, critical appraisal and clinical reasoning still has to be used when applying evidence.


Table 1: PICO(T) format example Best evidence available is most valid and reliable evidence that can be found for example in nursing intervention (example: patient education, hand hygiene). Best evidence available is typically based on current research on particular topic, but when the research evidence is weak or not available, other types of evidence can be used (eg. clinical guidelines, best practices).

Expertise in nursing means that a nurse has acquired the advanced knowledge base, complex decision-making skills and clinical competences for practice.

Patient preferences mean that nurses invites patients to be active participants in their care. It emphasizes the patient’s and her/his family members’ experiences with the illness or chronic condition. Nurses consider the biopsychosocial aspects of the illness, and decisions are made with the patient and with consideration of the patient’s perceptions and values.

Resources in EBN refer to physical and human resources, such as balanced workload of nurses, qualified, competent nurses, adequate nurse-patient ratio, equipment adequacy and appropriate physical structure of the nursing environment.

Well-composed PICO(T) questions generally contain up to four components each represented in the acronym «PICO(T)» P=Patient or Population and Problem; I=Intervention or Indicator; C=Comparison or Control (not part of all questions); O=Outcome; T=Time or Type.