Diagnostic test waiting times

We examine how long patients have to wait for a diagnostic test or procedure.


Last updated: 22/05/2020

Access and waiting times
Hospital care


Diagnostic tests or procedures are a critical element in 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, but diagnostic waiting times are now part of the NHS Constitution. This gives patients the legal right to have a diagnostic test within six weeks of the request being sent.

A review of NHS access standards is currently being undertaken, but the publication of recommendations has been delayed in light of the coronavirus (Covid-19) outbreak. The Interim Report proposed that the maximum six-week wait for diagnostic tests, with the threshold set at 99%, would remain unchanged.

The latest data presented here are for March 2020, and reflect changes in access and service use as a result of the coronavirus outbreak. 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. Note that this data does not include testing for coronavirus. See ‘About this data’ for the full list of tests included.

How has the percentage of patients waiting six weeks or more for a diagnostic test changed over time? 22/05/2020

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The proportion of patients waiting six weeks or more for a diagnostic test fell dramatically up until March 2008, when the diagnostic wait 'milestone' was introduced. Since then, the proportion of patients waiting longer than the target has mostly fluctuated at less than 3%. Only in the last two years have waiting times begun to increase again.

In June 2010, central performance management of targets was relaxed, and this corresponds to the increase in waits of six weeks or more that were recorded around the summer of 2011. The NHS Operating Framework 2012/13 introduced a further expectation that less 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 increased dramatically to 10.2%. This corresponds to a considerable decrease in the number of diagnostic tests performed, from 1.9 million in February 2020 to 1.5 million in March 2020, as elective care was put on hold to free up capacity for the response to the Covid-19 outbreak.

How many diagnostic tests are carried out and how many patients are on the waiting list? 22/05/2020

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The introduction of the six-week target also had a big 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. Since then the list has been steadily increasing, reaching a high of over 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, in March 2020 both the waiting list and number of diagnostic tests carried out fell considerably as a result of the Covid-19 outbreak. The waiting list fell to 838,569, 22% lower than in March 2019, and the number of tests carried out fell to 1.5 million, 23% lower than in March 2019. Although the number of diagnostic tests carried out decreased due to a reduction in hospital activity, there was also a drop in the number of tests being requested, resulting in an overall reduction of the waiting list.

Between February and March 2020, the average number of diagnostic tests carried out per day decreased for all 15 key tests or procedures included in this indicator. The largest decreases were for sleep studies (a 40% decrease), audiology assessments (a 38% decrease), and dual-energy x-ray absorptiometry (DEXA) scans (a 35% decrease).

How long do people wait on average for a diagnostic test? 22/05/2020

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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 over time. 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 March 2020, the median wait increased to 3.1 weeks, following the reduction in the number of diagnostic tests being carried out due to the Covid-19 outbreak.

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 that are included are:


  • Magnetic resonance imaging (MRI)
  • Computerised tomography (CT)
  • Non-obstetric ultrasound
  • Barium enema
  • Dual-energy x-ray absorptiometry (DEXA) Scan

Physiological measurements

  • Audiology assessments
  • Echocardiography
  • Electrophysiology
  • Neurophysiology – peripheral neurophysiology
  • Respiratory physiology – sleep studies
  • Urodynamics – pressures and flows


  • Gastroscopy
  • Colonoscopy
  • Flexible sigmoidoscopy
  • Cystoscopy

For further guidance on these data, please see the NHS England website.