Once you run searches in the databases using your PICO keywords and retrieve articles, you will need to appraise them for quality.
Depending on the type of study (the research design), a source will be considered a higher or lower level of evidence. This is also called the hierarchy of evidence or evidence pyramid.
Because of their rigorous design, systematic reviews and randomized control trials are considered high levels of evidence. Expert opinions and textbooks are considered low levels of evidence. When you search the literature, you can expect that as the quality increases, the number of studies will decrease.
Watch the brief video and read the article below to learn more about the levels of evidence that you will encounter in your searches of the nursing literature.
University of Louisville Libraries. (2018, January 30). Levels of evidence [Video]. YouTube.
Before any evidence is applied to your practice, you must first assess each article for relevance, possible bias, and validity. Check out the resources below to learn more about appraising evidence.
Critical Appraisal from Papers to Patient by
This book represents a brilliant primer and the tools and skills it equips the clinician with are designed to help them navigate the uncertainties of medical practice today. It is essential for those who wish to practice medicine in the best possible way for their patients.
Painless Evidence-Based Medicine by
This updated edition of Painless Evidence-Based Medicine presents basic concepts and application of research statistics in simple and practical manner creating an introductory approach to the complex and technical subject of evidence-based medicine from experienced teachers. A simplified introductory approach to the complex and technical subject of evidence-based medicine from experienced teachers Approaches learning from the vantage point of clinical questions on therapy, diagnosis, prognosis or harm rather than the framework of study designs Provides tables and boxed case studies throughout highlighting key topics, or difficult issues, in an easy to read manner Emphasizes applicability of EBM, encouraging readers to dissect the evidence and how results can be applied to individual patients with different circumstances, varying values and preferences New to the Second Edition are chapters on health screening, clinical practice guidelines, and major updates incorporating recommended trial criteria