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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.

Non-emergency (elective) surgery in England is influenced by the findings from clinical trials. But it can take years for practice to change in response to new research – if it does at all. New research investigated this “implementation gap” and assessed why actionable findings are – or are not – put into practice.

This research was based on 6 NIHR-funded clinical trials comparing different surgical approaches to planned procedures. The study authors assessed the use of different approaches, before and after a study’s publication. To understand more about why the evidence was acted on – or was not – the study authors also interviewed the original researchers and other healthcare professionals in the field.

They found that recommendations from half of the surgical clinical trials were implemented. Where recommendations were not put into practice, interviews showed the trial evidence was still considered, but evidence from other sources was also taken into account.

Funders often expect that single studies will lead to changes in clinical practice. The study authors say that changes should instead be built around all available evidence. They also believe funders should work in partnership with researchers to plan how their findings will be shared and implemented.

The issue: is research evidence put into practice?

Clinical trials compare treatments and procedures to determine which is better, safer, or more cost-effective. They are at the heart of evidence-based medicine and can improve clinical practice.

However, not all actionable findings are implemented. Even if they are, it can take many years for them to influence routine practice. There is a general lack of understanding as to why this is.

This study assessed whether actionable findings from 6 NIHR-funded clinical trials changed surgical practice in England. It looked at the rates of different planned surgical approaches before and after studies were published. The study authors asked surgeons and other healthcare professionals why the findings were – or were not – implemented.

What’s new?

This study was based on 6 clinical trials, funded by the NIHR between 2006 and 2015, which compared different surgical approaches. It looked at how often the different surgical approaches were used between 2001 and 2020. The study authors assessed whether the recommended approach was used more often after the publication of a paper, than before.

Researchers also interviewed 25 healthcare professionals (including researchers, surgeons, GPs, radiologists, and others) about why they thought the findings were or were not implemented.

For 3 studies, the findings were put into practice.  

  1. Feeding tubes through the nose (nasogastric) rather than through the skin directly into the stomach (percutaneous endoscopic gastrostomy) after stroke were recommended in a trial. It took a decade for practice to change. Interviews revealed that staff were initially reluctant to use nose feeding tubes because patients pulled them out. It took other studies showing the advantages of nose feeding tubes, and changes to guidelines from NICE (National Institute for Health and Care Excellence) to gradually shift practice.
  2. Removal of the under-surface of the kneecap (patella resurfacing) during a knee replacement was recommended in another trial. This practice increased before the trial was published and continued to increase after NICE guidelines were updated to recommend the procedure.
  3. Keyhole surgery to repair arteries (endovascular aneurysm repair) was recommended by a clinical trial; it found that procedures could be carried out  through a small cut in the groin instead of opening up the abdomen. Use of this procedure increased after the publication; NICE guidelines were also updated. But when later research showed that this surgery was less safe in the long-term, use of the procedure fell back. NICE guidelines were updated further to balance the short- and long-term outcomes.

In the remaining trials (2 on varicose veins, 1 on acid reflux), practice did not change in line with findings. The surgery recommended in the 2 varicose vein trials was not put into practice because other studies found that laser surgery worked better. Referrals for the surgery recommended in the acid reflux trial decreased as use of medical treatments increased.

Why is this important?

Clinical practice moved in the direction recommended by 3 of the 6 studies. Where findings were not implemented, there were good reasons for this. The authors found that the NHS was sensitive to emerging evidence in these areas of surgery.

Decision-makers seemed to respond to all available evidence. Recommendations were either implemented or, if they were not, there were valid reasons for this. Policymakers also considered patients’ quality of life when making decisions about managing conditions with medication or surgery.

This analysis focused on planned surgeries. The uptake of evidence and practice change may be different in other areas of medicine and surgery.

What’s next?

Researchers who carry out trials may not be the most appropriate people to encourage practice change based on their own findings, the study authors say. This is because practice change tends to follow consideration of all available evidence rather than just a single study.

The study authors recommend that funders work in partnership with researchers to plan how their findings will be shared and implemented. It would be helpful for them to have joint responsibility for ensuring the results are accessible and properly considered by the NHS and the research community.

Less emphasis should be placed on single studies leading to practice change, the study authors say. Patient choice and trade-offs in safety outcomes need to be considered; practice may not always reflect the recommendations of a single trial.  

You may be interested to read

This Alert was based on: Schmidtke KA, and others. Surgical implementation gap: an interrupted time series analysis with interviews examining the impact of surgical trials on surgical practice in England. British Medical Journal Quality and Safety 2022;0: 1-16.

A paper questioning the expectation that single studies will change practice: Claxton K, and others. Selecting treatments: a decision theoretic approachJournal of the Royal Statistical Society 2020;163: 211-25.

An analysis of the implementation of research in orthopaedics: Reeves K, and others. Implementation of research evidence in orthopaedics: a tale of three trialsBMJ Quality and Safety 2020;29: 374-81.

The need for a different approach to clinical research: Girling AJ, and others. Sample-size calculations for trials that inform individual treatment decisions: a ‘true-choice’ approachClinical Trials 2007;4: 15-24.

The impact of NIHR-funded studies: Hanney S, and others. An assessment of the impact of the NHS Health Technology Assessment ProgrammeHealth Technology Assessment 2007;11: 1-180.

More information about planning how to share your research with the people who can use it to effect change.

Funding: This study was supported by the NIHR Applied Research Centre West Midlands.

Conflicts of Interest: The authors declared no conflicts of interest.

Disclaimer: NIHR Alerts are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that views expressed in NIHR Alerts are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the Department of Health and Social Care.


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