At Sling the Mesh, we are pleased to see a powerful and thoughtful letter published in the prestigious journal Hernia by Nicholas T.H. Farr, titled “Absence of evidence is not evidence of absence – Rethinking NHS England’s inguinal hernia surgery decision aid.”

This is a landmark moment for everyone who has long called for greater transparency and scientific integrity in the way mesh-related risks are communicated to patients.

Farr’s letter is a masterclass in evidence-based critique. It challenges a key statement in NHS England’s decision support tool (DST) for inguinal hernia surgery, which claims that “none” of the patients experienced allergic or autoimmune reactions to hernia mesh.

Farr rightly points out that such a definitive claim is not supported by the available evidence – and more importantly, that it misrepresents the uncertainty that still exists in the scientific literature.

“Saying there is no evidence of an event is not the same as stating the event did not occur.”

This distinction is vital. It goes to the heart of informed consent and patient trust.

Farr’s letter highlights that while manufacturers of mesh products often include warnings about potential allergic reactions in their Instructions for Use (IFUs), the DST fails to reflect this nuance. Instead, it presents a level of certainty that the evidence simply doesn’t justify.

We applaud Farr’s call for the DST to be revised to say “no good data available” – a phrase that more accurately reflects the current state of knowledge and aligns with how other mesh-related risks are described in the same document.

This is not just a UK issue. It’s a global challenge: how do health systems communicate uncertainty without undermining clarity? Patients deserve to know not only what is known, but also what is not known.

At Sling the Mesh, we know how hard it can be to get these concerns taken seriously. We are delighted that Farr’s voice is now part of the scientific record, and strengthens the case for better, more honest communication in surgical decision-making.

Our advocacy shows patients aren’t tracked long enough to capture delayed mesh complications and research often focuses only on surgical success, not new symptoms, such as autoimmune responses, leaving many harms unrecorded in NHS data.

We hope the new Medical Devices Outcomes Registry (MDOR) – a major win for Sling The Mesh as part of our lobbying and a direct outcome of the First Do No Harm report led by Baroness Cumberlege – will begin to capture long-term complications of surgical mesh that are often missed in short-term studies.

Meantime, we encourage everyone – patients, clinicians, researchers, and policymakers – to read Farr’s letter and reflect on its implications. It’s a shining example of how respectful critique and scientific rigor can drive change.

 Read the full letter in Hernia journal “Absence of evidence is not evidence of absence”—Rethinking NHS England`s inguinal hernia surgery decision aid