Diagnostic tests or procedures are a critical part of the care of many patients. Shorter waiting times are beneficial as they help people get quicker access to the treatments they need.
The six-week diagnostic wait was initially introduced as a ‘milestone’ in March 2008 to support the achievement of the 18-week referral to treatment (RTT) target. Diagnostic waiting times are now part of the NHS Constitution, which pledges that patients should wait less than six weeks for a diagnostic test from the time that the request has been sent.
NHS England published new guidance in May 2021 for the prioritisation of waiting lists for diagnostic procedures. It states that waiting lists should be reviewed and prioritised according to clinical need rather than waiting time in areas where more than half of patients have been waiting for more than six weeks. In February 2022, NHS England proposed in the elective recovery plan that testing capacity will increase to 9 million more diagnostic tests by 2025 . More than 100 diagnostic centres are also set to be rolled out.
These indicators measure the waiting times of patients still waiting for any of 15 key diagnostic tests or procedures at the end of the month, not including testing for Covid-19. See ‘About this data’ for the full list of tests included.
Waiting list for diagnostic tests
The introduction of the six-week target in March 2008 also had an impact on the total number of patients on the waiting list for a diagnostic test or procedure. In December 2008, the waiting list fell to a low of just over 400,000 patients. Over time the list has increased, reaching more than one million people waiting for a diagnostic test in February 2020. This should be seen in the context of an increase in the number of diagnostic tests being undertaken each month: in July 2007, 995,098 diagnostic tests were carried out, and this almost doubled to reach 1.9 million in February 2020.
However, both the waiting list and number of diagnostic tests carried out fell as a result of the Covid-19 pandemic. Between February and April 2020, the waiting list fell by 22% to 841,049 and the number of tests carried out fell by 68% to 610,219. Since then, the waiting list has increased to almost 1.5 million in January 2022. The number of tests carried out has increased to 1.9 million, almost back to pre-pandemic levels.
NHS England’s guidance published in May 2021 states that waiting lists should be reviewed and prioritised based on clinical need in areas where more than half of patients have been waiting for more than six weeks.
Wait times of 6 weeks or more for a diagnostic test
From July 2006, the proportion of patients waiting six weeks or more for a diagnostic test fell until March 2008, when the diagnostic wait ‘milestone’ was introduced. In June 2010, central performance management of targets was relaxed, and this corresponded to an increase in waits of six weeks or more in the summer of 2011. The NHS Operating Framework 2012/13 introduced a further expectation that fewer than 1% of patients should wait six weeks or longer for a diagnostic test. The impact of this can be seen clearly, as from February 2012 to November 2013 the proportion stayed at around 1%. However, since then the 1% target has not been met.
In March 2020, the percentage of patients who had been waiting six weeks or more for a diagnostic test began to increase dramatically, reaching 58% in May 2020 – the highest level since records began. This corresponds to a sharp fall in the number of diagnostic tests performed, from 1.9 million in February 2020 to a low of 610,219 in April 2020, as non-urgent elective care was put on hold to free up capacity for the response to the Covid-19 pandemic. Performance has since improved, but remains considerably worse than before the pandemic. As of January 2022, 30% of patients had been waiting six weeks or more for a diagnostic test, equating to 434,996 people.
Wait times of 6 weeks or more by diagnostic test type
Of the 15 key diagnostic tests, the graph displayed above presents data from seven diagnostic tests with the largest test volumes (at least 50,000 tests conducted in January 2023).
In January 2023, 674,459 non-obstetric ultrasounds and 664,211 computed tomography or CT scans were conducted; these respectively accounted for 31% of the total volume of diagnostic test activity for that period. 344,340 magnetic resonance imaging tests or MRI scans were conducted, representing 16% of total diagnostic test activity. The rest of the tests each accounted for less than 7% of total activity.
In January 2023, 28% of people waiting for a non-obstetric ultrasound waited over 6 weeks. CT scans, despite having a similar volume of activity as ultrasounds, had a smaller percentage of people waiting over 6 weeks for a test (17%). MRI scans had half the total volume of activity than non-obstetric ultrasounds did, but a similar percentage of people waiting over 6 weeks (26%). Audiology assessments, echocardiographies, gastroscopies, and colonoscopies together accounted for only 9.6% of the volume of activity, but each had between 37-44% of people who needed a test waiting over 6 weeks.
Median wait times for a diagnostic test
In addition to looking at the proportion of people waiting six weeks or more for a diagnostic test, we can also examine changes in the median waiting time. In February 2008, the median waiting time fell to 1.9 weeks in anticipation of the introduction of the national target. The lowest median wait of 1.5 weeks occurred in January 2009.
Since then, the overall median wait has been slowly increasing. This is demonstrated by the rise in the 12-month rolling average, from 1.7 weeks in 2009 to 2.1 weeks in 2019. In general, the median wait peaks in December every year – this is likely due to people not being able to schedule or attend appointments over the Christmas holidays.
In May 2020, the median wait increased dramatically to 8.6 weeks, following the reduction in the number of diagnostic tests being carried out due to the Covid-19 pandemic. Since then, the median wait has decreased but remains higher than before the pandemic. In January 2022, the median wait was 3.1 weeks.
About this data
These indicators measure the waiting times of patients still waiting for any of 15 key diagnostic tests or procedures at the month end. The waiting times are for patients who have been referred for a test, but whose test had not taken place by the end of the reporting period.
Once a decision has been made that a patient needs a diagnostic test or procedure and the request has been sent, they are on the waiting list and the clock starts for their diagnostic test waiting time. The clock stops once they have had their diagnostic test or procedure.
The 15 key diagnostic tests are:
- Magnetic resonance imaging (MRI)
- Computerised tomography (CT)
- Non-obstetric ultrasound
- Barium enema
- Dual-energy x-ray absorptiometry (DEXA) scan
- Audiology assessments
- Neurophysiology – peripheral neurophysiology
- Respiratory physiology – sleep studies
- Urodynamics – pressures and flows
- Flexible sigmoidoscopy
For further guidance on this data, please see the NHS England website.