Background to the report

In June 2023, NHS England (NHSE) published its Long Term Workforce Plan (LTWP). Based on an extensive modelling exercise, the LTWP estimated a starting shortfall between workforce supply and demand of approximately 150,000 full-time equivalent (FTE) NHS workers.

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The LTWP projected NHSE’s estimate of the NHS’s health workforce needs and identified ways to meet them over the next 15 years, from a supply of 1.4 million FTE workers in 2021-22 to between 2.3 million and 2.4 million FTE workers in 2036-37, an increase of 65% to 72%.

NHSE has committed to continue to develop its modelling and the LTWP, publishing a refreshed projection every two years, or aligned with fiscal events as appropriate.

Scope of the report

After a request from HM Treasury (HMT), the Department of Health & Social Care (DHSC) and NHSE, the Comptroller & Auditor General agreed that the National Audit Office (NAO) would carry out an independent assessment of the modelling underpinning the LTWP. Our scope was as follows:

  • to consider whether NHSE constructed its models effectively and whether they operated correctly in a technical sense to generate the projections and other outputs required of them
  • to consider whether NHSE’s approach to workforce modelling and the models themselves are a reasonable basis for regular strategic workforce planning


NHSE has rapidly, and for the first time, produced modelling that brings together its planning of future NHS health services with its longer-term assessment of the workforce it thinks will be required to deliver them. This is a significant achievement, which provides a foundation for NHSE to build on.

We welcome its commitment to improve the modelling as part of the regular planned updates to the LTWP. In our model assessment, we found that the methods used in the Python model in NHSE’s modelling pipeline represented a reasonable technical approach to health workforce modelling, and we were able to replicate the outputs from this part of the modelling.

However, this first version of the modelling pipeline as a whole has significant weaknesses, including the lack of integration between different parts of the pipeline and the manual adjustments to balance supply and demand gaps in the triangulation models.

We found that limitations in documentation and the use of manual processing meant we were not able to fully replicate the results of the modelling as an independent reviewer. Some of the assumptions used in the modelling may be optimistic and the model outputs were weakened by the limited extent to which future uncertainties were communicated. NHSE needs to address these issues in order for the modelling to be a reasonable basis for regular strategic workforce planning.

Workforce modelling is highly unlikely to produce a single “correct” answer on how many health professionals will be needed in future. In this context, modelling is really an evidence-based and transparent tool for beginning a conversation, including with external stakeholders, about the desirability and feasibility of different approaches and policies.

Our recommendations below and throughout this report are intended to assist NHSE in making its modelling more useful and providing ministers and officials with a better basis for reaching decisions in future.

While the decisions taken as part of the LTWP are out of the scope of our review, we note that government has only committed funding up to 2028-29 and that NHSE plans to make changes in stages. This gives NHSE a built-in opportunity to make adjustments, for example to the number of training places, after it has revisited the modelling.


Publication details

Press release

View press release (22 Mar 2024)

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