How is the growth in diagnostic testing affecting NHS practice?

The number of diagnostic tests carried out in primary and secondary care has grown rapidly over the last two decades. This trend is likely to continue given the key role that testing will play in achieving NHS commitments around cancer and heart disease.  An increase in diagnostic testing brings benefits. Yet, there has been limited consideration of the indirect effects of this growth. A rare study into the rising number of diagnostic procedures in primary care suggested that “increased diagnostics earlier in pathways can burden patients and stretch general practice workloads, inducing downstream service utilisation and unintended ‘market failure’ effects.”[i]

Meanwhile, in secondary care, growth in diagnostic testing has likely increased referral to treatment (RTT) times, A&E waits and inpatient length of stay.

Responding to the major growth in diagnostic testing observed over last two decades, this report will investigate:

1. A range of diagnostic disciplines, including imaging, endoscopy and physiological measurements.
2. The trends in various diagnostic activities over time.
3. The effect of the growth on processes and flows within the NHS and the unintended consequences of the rapid increase in diagnostic testing.
4. The trajectory of diagnostic testing, and the potential impact of continued growth.
5. Potential mitigations for difficulties that may arise from continued growth in diagnostics.

We will do this by:

• Setting out the current situation, examining trends in diagnostic testing and identifying the types of activity that are driving growth currently. We will illustrate how costs* and positivity rates* have changed in recent years. ​*where available
• Describing the impact that the growth in diagnostic testing has had on patients, processes, and flows. We will pay particular attention to the effects in secondary care. An increase in testing has likely affected referral to treatment (RTT) times, A&E waits, and inpatient length of stay.
• Examining the current projections, and asking questions such as: How many tests might we expect by 2025, and 2030? What would it look like if the UK had the same test rates as Germany or the US? And, given the findings from the second point above, what might be the impact of such increases?
• Finally, exploring ways to mitigate the difficulties that may arise due to the continuing growth of diagnostic services.

A detailed written report will be compiled setting out the objectives, methods, data sources, results and conclusions and shared on our website.

All code (R and T-SQL) will be published on GitHub and accessible to DSU Network members

We may also publish in a peer-reviewed or trade journal

[i] Sajid IM, Frost K, Paul AK. ‘Diagnostic downshift’: clinical and system consequences of extrapolating secondary care testing tactics to primary care. BMJ Evid Based Med. 2021 Jun 7:bmjebm-2020-111629. doi: 10.1136/bmjebm-2020-111629. Epub ahead of print. PMID: 34099498.