Evidence Basics
Studies estimate that only one in twenty commonly used healthcare treatments are supported by good evidence of effectiveness. Evidence-based Medicine provides clinicians with recommendations for treatment based on high-quality evidence. Both government agencies and non-government organizations evaluate evidence for treatments, create treatment guidelines, and share recommendations with providers so they can be used to improve patient health.
However, guidelines for clinicians to use EBM can be compromised by conflicts of interest by the people tasked with developing them. Despite challenges, EBM remains an important method for delivering high-quality, evidence-based decision-making. EBM can improve patient’s quality of care and help support clinicians in providing the most effective therapy.
Evidence Deeper Dive
Evidence-based medicine (EBM), also called evidence-based practice (EBP), is a decision-making tool used by clinicians. EBM is based on the best available evidence instead of personal beliefs or traditions. Sacket et al., in 1996, defined EBM as “the conscientious and judicious use of current best evidence from clinical care research in the management of individual patients.”
EBM can be used when deciding the best treatments such as antibiotics for a urinary tract infection or glycemic control in diabetic patients.
According to the Centers for Disease Control (CDC) and Centers for Medicaid and Medicare System (CMS) data, 90% of the $4.1 trillion spent on US healthcare expenditure goes to treat chronic diseases and mental health conditions. Adopting evidence-based approaches and understanding evidence utilization to improve decision-making is essential in addressing complex chronic diseases, increased healthcare expenditures, and decreased access.
Evidence-based practices yield high-quality care, improved health outcomes, positively impact cost, and reduce the variability of care.
EBM integrates strong evidence from well-conducted research and the clinician’s expertise, with the individual patient’s values, preferences, and expectations. Clinicians use evidence-based medicine to inform their clinical practice based on guidelines. EBM ensures that medical treatments are cost-effective, efficient, and effective. The goal is to make informed clinical decisions to deliver high-quality patient-centered care and improve patient outcomes.
Using the best available evidence
Healthcare providers use evidence-based guidelines developed from high-quality research, preferably randomized controlled trials (RCT), to guide interventions and management. RCTs are the gold standard for evaluating the effectiveness of medical therapies. RCT studies provide the most substantial evidence in research, followed by observational studies. High-quality research, free of bias, informs the guidelines for best practice. It should be free of systematic research bias, poorly designed research trials, or publication and reporting bias. The EBP approach involves an ongoing review by clinicians of research, peer-reviewed publications, and literature, so effective policies and guidelines are developed from high-quality research.
Clinical Practice Guidelines (CPG) are recommendations for providing evidence-based care and informing screening, diagnosis, and treatment of diseases. However, guidelines are too often affected by conflicts of interest (COI). COIs arise when the people developing the guidelines are biased, either with financial ties to pharmaceutical, medical device, and biotechnology companies that may benefit from clinicians adhering to the guidelines or personal biases such as previous research or statements favoring a treatment over others.
In 2011, the National Academy of Medicine, formerly the Institute of Medicine, published a trustworthy guideline outlining the clinical practice guideline standards. Unfortunately, CPG developers don’t always adhere to NAM standards. Previously, guidelines were developed by a panel committee that included subspecialty experts and specialists from academia, often with COIs. Some interventions previously recommended based on guidelines were eventually found to be harmful.
- Hormone replacement therapy to prevent breast cancer was later found to increase breast cancer.
- Beta-blockers were recommended to decrease mortality despite weak evidence.
- A guideline recommended a high dose of Vancomycin which subsequently leads to kidney failure
Guidelines should evolve as new high-quality evidence becomes available. A large review of 1,567 healthcare treatments found that 95% of treatments were not supported by high-quality evidence. Potential harms of the treatments were reported only about 33% of the time. Cochrane Review, a respected, independent nonprofit organization, developed a system called grading quality of evidence and strength of recommendation (Grade). This widely accepted system has a four point rating scale for the trustworthiness of the evidence. The ratings are — very low, low, moderate, and high.
| Certainty | What it means |
| Very Low | The true effect is probably markedly different from the estimated effect. |
| Low | The true effect might be markedly different from the estimated effect. |
| Moderate | The true effect is probably close to the estimated effect. |
| High | There is a great deal of confidence that the true effect is similar to the estimated effect. |
A 2020 analysis of Cochrane guideline reviews of guidelines found that only 10 % of medical treatments were based on high quality research. The quality of evidence for making treatment decisions remains low.
The Preventive Services Task Force (USPSTF or Task Force) is a panel of primary care and evidence-based medicine experts appointed by the Director of the Agency for Healthcare Research and Quality (AHRQ) within the Department of Health and Human Services (HHS). USPSTF uses evidence to develop a comprehensive plan for inclusive and equitable development and dissemination of preventative measures. The Task Force systemically reviews topic-specific research and decides whether reliable, high-quality evidence is available to support the treatment. Recommendations are based on the balance of benefits compared to harms and the strength of the evidence.
| Grade | Definition | Practice Suggestions |
| A USPSTF recommends the service | High certainty that the net benefit is substantial | Offer or provide this service |
| B USPSTF recommends the service | High certainty that the net benefit is moderate; or there is moderate certainty that the net benefit is moderate to substantial | Offer or provide this service |
| C USPSTF recommends selectively offering or providing this service to individual patients based on professional judgment and patient preferences | There is at least moderate certainty that the net benefit is small | Provide or offer the service for select patients depending on individual circumstances |
| D USPSTF recommends against the service. | There is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits | Discourage the use of the service |
| I USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and or harms of the service | Evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined | Read the clinical considerations section of USPSTF Recommendation Statement. If the service is offered, patients should understand the uncertainty about the balance of benefits and harms. |
To expand comparative effectiveness research on which treatments work, the ACA created a non-profit Patient-Centered Outcomes Research Institute. PCORI funds researchers, sets priorities for which treatments to evaluate, and gives patients and others information they can use in making healthcare choices. PCORI’s work has been controversial, especially with healthcare industries. To address the concerns, the ACA prohibits PCORI’s findings from being “construed as mandates for practice guidelines, coverage recommendations, payment, or policy recommendations.” PCORI has been a leader in shifting the focus of evidence to outcomes that matter to patients by engaging patients at every step of their work. PCORI has been awarded $3 billion for over 2,000 research projects. However, concerns have been raised that PCORI’s findings have not been adopted by healthcare providers in their practice.
The nonprofit Institute for Clinical and Economic Review is an independent, influential information source providing policymakers and other payers with expert, independent information on both the effectiveness and fair prices for drugs and other treatments. ICER’s assessments frequently suggest significantly lower prices for treatments that do not provide added benefit while supporting higher prices for treatments that do, maintaining strong financial incentives for innovative new treatments.
ICER’s research is widely used by clinicians, federal agencies, insurers, employer plans, and state policymakers to set reasonable prices for drugs and other treatments. ICER’s reports include evidence-based calculations of prices for new drugs that accurately reflect expected improvement in long-term patient outcomes while also highlighting price levels likely to be unaffordable for the overall healthcare system. ICER relies on scientific studies combined with patient and patient organization input in developing their reports.
Annually, ICER reports on significant drug price increases that are not supported by either new research on the clinical benefit to patients or increases in costs to manufacture. ICER’s 2021 report found that seven drugs with unsupported price increases caused $1.67 billion in higher drug spending. ICER’s analysis of fair access policies led six national insurers to change restrictive policies making treatments more available to patients.
EBM requires clinician expertise and judgment
Trustworthiness of the evidence by clinicians is important. There is a significant amount of research and literature available to clinicians for review. Clinicians must go through a large amount of published research on a particular topic critiquing the validity, reliability, and applicability of the research finding.
Challenges to EBM
Not all guidelines are created equal. Strong evidence must be present to support guidelines. Conflicts of interest too often influence the types of evidence labelled “Best evidence.” A 2021 study found that 22% of organizations that generated over five clinical practice guidelines in two years failed to have a conflict of interest policy. Only 6% of organizations that develop conflict of interest guidelines require their members to disclose how the conflict of interest could impact the guideline development process. Conflict of interest both financial and non-financial, impact the evidence presented in clinical practice guidelines.
There are many challenges to implementing the practice of EBM, including the belief in evidence. Organizational culture regarding EBM, leadership support and resources, and availability of knowledge brokers to help facilitate EBM. Implementation of EBM varies globally and there is a lack of processes that support the implementation of EBM.
Expanding evidence in healthcare
Despite challenges, EBM remains an important method for delivering high-quality, evidence-based decision-making. EBM can improve patient’s quality of care and help support clinicians in providing the most effective therapy.
Written by Chizoro Taylor, MS, PA-C