Evidence Based Information
Evidence-based health and wellness information is information, guidance, or recommendations that are grounded in the best available scientific evidence rather than being based primarily on personal opinion, tradition, popularity, advertising, anecdotal experience, or untested theory. Evidence-based information is developed by identifying relevant research, evaluating the quality and limitations of that research, and presenting conclusions that accurately reflect what the overall body of evidence currently supports.
The evidence should come from appropriately designed scientific studies published by credible sources and, when available, evaluated through peer review, systematic reviews, meta-analyses, evidence-based clinical guidelines, or other structured methods intended to reduce bias. Systematic reviews are especially valuable because they use explicit procedures to locate, evaluate, and synthesize the available research addressing a particular question.
Evidence-based does not mean that a statement has been proven with absolute certainty. Scientific conclusions may change as new research becomes available, previous findings are replicated or challenged, research methods improve, or previously unidentified benefits and risks are discovered. For this reason, evidence-based health information should accurately describe the strength, consistency, relevance, and limitations of the available evidence. It should distinguish among well-established conclusions, reasonably supported conclusions, preliminary findings, expert consensus, theoretical explanations, and claims for which adequate evidence is not yet available.
The strength of evidence also depends on the question being asked. Randomized controlled trials and systematic reviews of controlled trials are often particularly useful for determining whether a treatment or intervention produces a specific outcome. Observational studies may be necessary for examining long-term effects, uncommon harms, risk factors, prognosis, environmental influences, or circumstances in which controlled experimentation would be unethical or impractical. Qualitative research may provide important evidence about personal experiences, cultural considerations, treatment acceptability, accessibility, and barriers to care. Therefore, evidence should not be evaluated solely by study type; it should also be assessed for methodological quality, relevance, consistency, applicability, possible bias, and whether the conclusions are justified by the data.
Evidence-based health and wellness information should generally meet the following standard: it is consistent with the best scientific evidence available at the time; it comes from identifiable and credible sources; it has been reviewed for accuracy, objectivity, completeness, and scientific integrity; it distinguishes association from causation; it acknowledges uncertainty and conflicting findings; it identifies significant risks, benefits, and alternatives; and it is updated when the evidence materially changes.
In practice, health-related decisions should usually be described as evidence-informed rather than determined by research evidence alone. Evidence-informed decision-making combines the best available research with professional expertise, clinical judgment, ethical and legal standards, individual circumstances, personal values, cultural context, available resources, accessibility, and the preferences and goals of the person receiving the information or service. The World Health Organization describes evidence-informed decision-making as the process of identifying, appraising, and applying the best available evidence to support safe and effective health policies and practices.
A health or wellness claim should not be considered evidence-based merely because it uses scientific terminology, cites a single study, includes testimonials, is promoted by a licensed professional, or appears on a professional-looking website. A single study may provide useful evidence, but its findings must be interpreted in relation to the study’s design, sample size, population, comparison conditions, outcome measures, conflicts of interest, statistical and clinical significance, replication, and consistency with the broader scientific literature.
Accordingly, evidence-based health and wellness information may be defined as:
Information that accurately represents the best currently available and relevant scientific evidence; has been critically evaluated for quality, bias, consistency, benefits, risks, and limitations; and is communicated transparently so that individuals and qualified professionals can make informed decisions in consideration of the person’s needs, values, circumstances, and goals.
Evidence-based information supports informed decision-making but does not replace individualized assessment, diagnosis, medical care, mental health treatment, or consultation with an appropriately qualified healthcare professional.
References
Centers for Disease Control and Prevention. (2024). Information quality support: Science and peer review.
Cochrane. (2024). Cochrane handbook for systematic reviews of interventions.
Kington, R. S., Arnesen, S., Chou, W. Y. S., Curry, S. J., Lazer, D., & Villarruel, A. M. (2021). Identifying credible sources of health information in social media: Principles and attributes. NAM Perspectives.
Wallace, S. S., Barak, G., Truong, G., & Parker, M. W. (2022). Hierarchy of evidence within the medical literature. Hospital Pediatrics, 12(8), 745–750.
World Health Organization. (2022). Evidence, policy, impact: WHO guide for evidence-informed decision-making.