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April 2026: Thirlwall Inquiry final report due after Easter · CCRC still reviewing 31+ independent expert reports · Shoo Lee Panel (Feb 2025): no medical evidence of deliberate harm.

Lucy Letby Facts

Long-form · Documentary record

The Datix record

Datix is the NHS incident-reporting system. Every unexpected event on a ward — equipment failure, medication error, fall, crash call, infrastructure incident — is supposed to generate a Datix entry. The Countess of Chester neonatal unit’s 2015–16 Datix record, partially examined at the Thirlwall Inquiry, tells a story the trial jury was not systematically walked through.

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What Datix is for

Datix is a database, used across the NHS, for incident reporting. A clinician, nurse, porter or patient can log an event. The event is then triaged for severity, investigated, and used to drive learning. The system is a cornerstone of NHS patient-safety policy. Every Trust runs one. The Countess of Chester had one in 2015–16.

Datix entries are, for an independent reviewer, a contemporaneous record of how the unit was functioning as experienced by the people on it. Unlike trial testimony reconstructed years later, they are written in the moment, usually by a person who cannot yet know that the entry will be scrutinised.

What the Countess of Chester Datix record contains

Thirlwall Inquiry evidence bundles have placed significant portions of the 2015–16 Datix record into public evidence. The categories of incident logged are, on the record itself, incompatible with the Crown’s implicit assumption of a clinically well-functioning unit on which one nurse was the only anomaly. Specifically:

  • Plumbing and sewage incidents. Recurrent incidents logged across 2015 and 2016, corresponding to the Lorenzo Mansutti defence-witness testimony. Sewage-back-up and plumbing-failure incidents on a neonatal unit are a recognised route for environmental pathogen introduction.
  • Infection-control incidents. The documented outbreak of a multi-drug resistant bacterial pathogen, detailed in the September 2024 Guardian investigation, is reflected in the unit’s Datix infection-control entries for the same period.
  • Pharmacy and medication incidents. Issues with drug storage, labelling, and TPN-bag handling were logged. The prosecution’s insulin-spiked-TPN-bag theory rests on secure TPN-bag handling; the Datix record documents that TPN-bag handling on this unit was not reliably secure.
  • Staffing-incident entries. Multiple Datix entries log inadequate staffing (nursing and medical) on specific shifts. The Guardian investigation’s doctor-shortage picture is mirrored in the Datix log of specific incidents where staffing prevented adequate clinical response.
  • Equipment failures. Entries logging malfunctioning incubators, ventilators, and monitoring equipment across the cluster period.
  • Clinical-deterioration entries. The unexpected deaths and collapses themselves — including ones outside the indictment — were Datix-logged in the usual way.

What the Datix record collectively shows

Read together, the Datix record is the picture of a unit functioning at the limits of, and sometimes beyond, its operational envelope. It is the picture the Guardian investigation describes, the picture Lorenzo Mansutti’s defence testimony supports, and the picture Dr Brearey’s Thirlwall Inquiry evidence confirms: staffing was thin, infrastructure was stressed, infection control was under pressure, and the babies being admitted were often sicker than the unit was designed for.

A cluster of deaths on such a unit is, in the language of patient-safety epidemiology, a signal of systemic strain rather than a signal of a single actor. The signal does not itself prove that all deaths had natural or systemic causes — but it does prove that natural and systemic causes are available explanations that a properly conducted investigation would have examined.

Why the jury did not see this

The defence raised elements of the Datix record at trial, and Lorenzo Mansutti’s testimony (see our summary) addressed the plumbing-sewage dimension directly. But the Datix record was not presented to the jury as a single, systematic body of evidence. The prosecution’s narrative was built around individual incidents; the Datix record spoke to the context around the incidents. Those are different things.

At the Thirlwall Inquiry in 2024, counsel to the Inquiry presented much more of the Datix record systematically, precisely because the Inquiry’s remit is institutional response. What the Inquiry saw was context-heavy. What the jury saw was context-light.

What the CCRC can do with this

The Datix record is not “new evidence” in the strict sense that it did not exist at trial. It did exist, and parts of it were before the jury. What is new is the comprehensive, systematic reading of it made possible by the Thirlwall Inquiry’s disclosure process. The CCRC’s statutory “real possibility” test can be met by new readings of existing material as well as by materially new material.

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