Chelsea and Westminster FDP success ‘flawed’, finds analysis

A BMJ article has criticised data used to support claims about the impact of the NHS federated data platform (FDP) as “flawed”.

US software firm Palantir signed a £330m contract in 2023 to provide the FDP, which connects data across NHS organisations.

A study, published by BMJ Health Care Informatics on 12 March, found that the platform’s implementation was linked to improvements in theatre utilisation at Chelsea and Westminster Hospital and West Middlesex University Hospital in January 2022.

However, internal NHS data seen by the BMJ suggest that the data show “no meaningful difference between FDP adopters and non-adopters” and suggested that the study’s conclusion “conflates correlation with causation”.

An article by Rhiannon Mihranian Osborne, published on 13 April, suggests that “the performance improvements attributed to the FDP would have occurred regardless, as the health service recovered from the pandemic”.

It highlights that the study’s baseline performance period ended in December 2021, during the height of the omicron wave in the Covid-19 pandemic, when trusts were experiencing extreme staff sickness, cancelled elective activity, and severe operational disruption.

The article adds that from late 2020 through 2022, Chelsea and Westminster and other trusts in the region follow almost identical trajectories: sharp performance declines during Covid waves, followed by recovery as pressures eased and it was this low baseline performance which the FDP theatre management tool was compared with.

“Critics highlight that using this period all but guarantees that recovery after December 2021 would be interpreted as success of the theatre management tool,” the article states.

Louis Mosley, executive vice chair of Palantir UK, which holds the contract for the FDP, posted on X criticising the article.

When your doctor prescribes a treatment, the evidence behind it was probably published in a journal like the British Medical Journal, or BMJ for short.

The BMJ proved smoking caused cancer. It pioneered the randomised controlled trial. It is one of the four most cited medical… pic.twitter.com/ToQM8MBqGC

— Louis Mosley (@louismosley) April 21, 2026

He added on X that the article was “technically accurate, engineered to mislead”.

“The baseline is actually a 45-week trend. The study’s authors flagged the Omicron endpoint themselves. The BMJ just forgot to mention any of that preceding period and want to lean heavily on the Omicron endpoint itself,” he said.

Mosley also argued that The BMJ had not clearly disclosed that author Osborne, has a “long-standing and public ethical objection to Palantir”, which he said was evident in this article from August 2024.

In response, Kamran Abbasi, editor in chief at The BMJ told Digital Health News: “The research article that he refers to was published in BMJ Health & Care Informatics, another journal from BMJ Group, and the study’s limitations that question its basis for scaling up the FDP are clearly acknowledged.

“As with all observational studies, the findings can’t establish direct cause and effect.”

Imperial College Projects has been awarded a £700,000 contract by NHS England to evaluate the FDP with findings expected in 2029.

Meanwhile, health minister Zubir Ahmed has signalled that the government could consider alternatives to the FDP when the contract reaches its break clause later this year.

Digital Health News contacted NHS England for comment.