Why Evidence Is Not Always Adopted Quickly: Understanding the Gap Between Discovery and Practice
One of the biggest challenges we have in implementing precision medicine is the significant gap between clinical guidelines, insurance coverage and what is in the medical literature. There are significant scientific, legal, business, political and social barriers between translating the actual research into practice.
Three examples came up in the news recently that illustrated the challenge.
Chronic Lyme: A Change in Perceptions
In the Wall Street Journal recently there was an article entitled “Chronic Lyme Disease was once dismissed. More doctors are coming around.”
This article highlights the slow adoption of new evidence. Research has consistently shown that it takes an average of 17 years for evidence-based treatments to reach clinical practice[1][2]. This means that potentially life-changing discoveries sit on the shelf while patients continue to receive outdated care
The country’s experience with post-COVID syndrome the last four years is starting to change perceptions around fatiguing illnesses whether they are from Lyme, other viruses or toxicants. The parallel between chronic Lyme and long COVID is particularly striking. Recent NIH research shows that 4.5% of COVID-19 survivors develop myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), compared to less than 1% of uninfected individuals[4][5]. This has forced the medical community to reconsider its dismissive attitude toward post-infectious syndromes.
The largest NIH-funded study to date is now following Lyme patients from their earliest diagnosis to understand why some develop persistent symptoms[6][7]. This represents a sea change from decades of denial. Yet many physicians still refuse to acknowledge chronic Lyme, leaving patients to navigate a medical system that questions their suffering.
Bioidentical Hormones: A Narrative Gone Awry
On the Megyn Kelley show , Megyn had a good discussion with Dr. Marty Makary, the FDA commissioner on the benefits of bioidentical hormones for women. This has been a critical part of our protocols for brain health, but many patients have been skeptical because their ob-gyns said it was not part of evidence-based medicine.
Marty revealed the truth behind this misalignment. The initial research from the Women’s Health Initiative in the early 2000s NEVER showed that there was a relationship between cancer and bioidentical hormones. Rather the senior researcher thought it was in the public interest that women were informed of the potential risk even though the data didn’t show it. The media and medicine ran with the headline even though the data was not supporting.
This created a 20-year period where women were denied potentially beneficial hormone therapy based on a misinterpretation. Recent analyses confirm that the original WHI data actually showed no increased risk with bioidentical hormones, and even suggested protective effects in some age groups[10][11]. Yet 15 years later, as the spotlight was shined on this issue and there has been a general retraction in the medical literature on this topic, physicians are slow to respond and habits are hard to break.
Hyperbarics: Different Coverage Policies
Hyperbaric oxygen is another therapy that we find to be critical at Rezilir Health. There is now outstanding randomized controlled clinical trial data out of Israel showing the evidence supporting HBOT for neurological conditions continues to mount[12][13]. Studies show significant improvements in:
- Post-stroke recovery, even years after injury
- Traumatic brain injury outcomes
- PTSD symptoms in combat veterans
- Fibromyalgia and chronic pain syndromes
- Post-COVID neurological symptoms
A recent double-blind randomized trial showed that HBOT recipients had significantly better outcomes than controls, with improvements in neurological function scores and quality of life measures[14]. The University of South Florida is conducting a $28 million state-funded trial specifically because the evidence is so compelling[15].
However, there seems to be a bias in the US insurance system review of data in accepting international studies. Many of the Israeli studies don’t show up in the meta-analyses. As a result, US patients are denied coverage for critical care that their Israeli counterparts get routinely covered. In this case, it’s not an issue of evidence, it’s an issue of slow coverage determination and institutional bias.
Understanding the Barriers
Why does it take so long for evidence to change practice? Research identifies several key barriers that perpetuate this problem:
Institutional Factors (30%): Medical education remains remarkably resistant to change[20][21]. The phrase “we’ve always done it this way” is deeply embedded in medical culture. Medical schools still teach using methods developed over a century ago, and many physicians practice based on what they learned in training rather than current evidence.
Economic Factors (25%): Insurance companies are slow to approve coverage for new treatments[22][23]. Pharmaceutical companies may suppress negative results or promote older, profitable treatments over newer, more effective ones[24]. The reimbursement system often penalizes innovation by paying less for treatments that require fewer visits or procedures.
Cultural Factors (20%): Medicine has a hierarchical culture that resists challenges to established authorities[25][26]. Young physicians who question established practices face career consequences. The “Semmelweis reflex”—the tendency to reject new evidence that contradicts established beliefs—remains alive and well[27].
Research Issues (15%): Publication bias means negative studies often aren’t published[28][29]. It can take years for research to go through peer review. Even when published, dissemination to practicing physicians is limited. Many doctors simply don’t have time to keep up with new research.
Regulatory Delays (10%): FDA approval processes, while important for safety, can delay access to beneficial treatments[30]. Coverage determinations by Medicare and insurance companies add additional years of delay.
Moving Forward: Bridging the Gap
The good news is that awareness of this problem is growing. Implementation science—the study of how to get evidence into practice—is gaining recognition[3][37]. Some institutions are pioneering integrated evidence generation approaches that involve all stakeholders from the beginning[38].
For patients, this means being informed advocates for your own care. When your doctor dismisses a treatment as “unproven,” ask whether they mean there’s no evidence, or whether the evidence simply hasn’t been incorporated into standard guidelines yet. The difference can be decades.
At Rezilir Health, we’re committed to staying ahead of the curve, incorporating evidence as it emerges rather than waiting decades for official approval. Whether it’s recognizing chronic Lyme, using bioidentical hormones appropriately, or offering hyperbaric oxygen therapy, we believe our patients deserve access to treatments supported by science—even if the medical establishment hasn’t caught up yet.
The 17-year gap between evidence and practice isn’t inevitable. It’s a choice—one that the medical system makes every day. By understanding these delays and their causes, we can work together to ensure that evidence-based care reaches patients when they need it, not decades later.
References:
- https://pubmed.ncbi.nlm.nih.gov/37018006/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC3241518/
- https://www.myamericannurse.com/implementation-linchpin-evidence-based-practice-changes/
- https://www.cidrap.umn.edu/covid-19/1-20-covid-survivors-may-have-condition-characterized-extreme-fatigue
- https://www.nih.gov/news-events/news-releases/nih-funded-study-finds-cases-me/cfs-increase-following-sars-cov-2
- https://medicine.tufts.edu/news-events/news/large-scale-study-will-seek-unearth-causes-persistent-symptoms-lyme-disease
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11893417/
- https://gremjournal.com/journal/02-2024/menopausal-hormone-therapy-and-breast-cancer-risk-21-years-from-the-whi-clinical-studies/
- https://journalofethics.ama-assn.org/article/after-womens-health-initiative-menopausal-women-and-hormone-therapy/2005-11
- https://www.bcrf.org/about-breast-cancer/hrt-breast-cancer-risk/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC6808563/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8130666/
- https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2024.1450134/full
- https://www.nature.com/articles/s41598-025-86631-6
- https://www.usf.edu/health/news/2024/speaker-renner-visits-hbot-center.aspx
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11568873/
- https://www.nationalgeographic.com/history/article/handwashing-once-controversial-medical-advice
- https://pmc.ncbi.nlm.nih.gov/articles/PMC1283743/
- https://www.nobelprize.org/prizes/medicine/2005/press-release/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5723723/
- https://kevinmd.com/2024/05/modernize-medical-education-or-face-failure.html
- https://paragoninstitute.org/medicare/roadblock-to-progress-how-medicare-impedes-health-care-innovation/
- https://www.mercatus.org/research/policy-briefs/how-medicare-hindering-healthcare-innovation-and-way-forward
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11284809/
- https://www.sciencedirect.com/science/article/abs/pii/S1212411718300114
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10494351/
- https://fems-microbiology.org/femsmicroblog-handwashing-a-symbol-of-resistance/
- https://pubmed.ncbi.nlm.nih.gov/2406473/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC6573059/
- https://www.jmcp.org/doi/10.18553/jmcp.2022.28.7.732
- https://academic.oup.com/jcem/article/96/7/1911/2833671
- https://www.ccjm.org/content/89/3/154
- https://comprehensivepain.com/blog/cognitive-behavioral-therapy-and-chronic-pain
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5999451/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC155637/
- https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.118.313348
- https://pmc.ncbi.nlm.nih.gov/articles/PMC12126355/
- https://www.mckinsey.com/industries/life-sciences/our-insights/integrated-evidence-generation-a-paradigm-shift-in-biopharma
