Mortality, quality of life, length of stay, avoidable adverse events and patient and/or carer satisfaction were considered by the committee to be critical outcomes.

Interval between request and receipt of result or report by the requesting healthcare professional, time to definitive diagnosis, staff satisfaction and representation were considered to be important outcomes.

The committee prioritised access to 7 day diagnostic CT, MRI, ultrasound and nuclear medicine. The committee identified plain film x-ray as an area where a 7-day service was routinely offered, and therefore they did not include this intervention within the evidence review as it would not change current practice. The provision of these services included 24/7, 7-day extended working, 7-day working (9am-5pm), 6-day working, and 5-day working. No evidence was identified for any combination of these.

The committee considered the benefits of access to diagnostic radiology 7 days a week to be critical for many acute medical emergencies to ensure accurate diagnosis and timely and effective treatment. For example, immediate access to CT scans is essential for the investigation of suspected pulmonary embolism, intracranial haemorrhage and thoracic dissection. There are no anticipated harms in providing 7-day diagnostic radiology, if fully resourced. However, if shortages in radiology and radiography staff persist then there is potential for harm through spreading staff more thinly across the week or diverting them from other activities..

The committee discussed the lack of evidence identified and opted to develop a research recommendation.

No economic evidence was identified. Unit costs were presented to the committee (Chapter 41 Appendix I).

No economic analysis could be conducted due to a lack of evidence on the benefits and harms. Increasing the provision and access to diagnostic radiology might require an increase in “up front” resources and therefore cost. This would include additional staff time and investment in radiology equipment and machinery where there is currently little provision. The current shortage of trained radiology and radiography staff means that the opportunity cost of expanding services is likely to be higher than that suggested by salary levels, since there is a need to recruit or train additional staff.

Although the committee felt that it was likely to have a benefit and could potentially cause a decrease in length of stay, there was no evidence to show the cost impact or magnitude of benefit needed for the provision of a 7 day diagnostic service to be a cost-effective use of NHS resources.

The committee decided that a recommendation could not be made due to a lack of evidence and therefore opted to form a research recommendation.

Currently there are varying levels of access to different types of radiology. The most common radiological investigations used for AME are plain film chest x-rays and CT scans. All hospitals should have 24/7 access to the former and most will have 24/7 access to the latter, both of which are critical for many AME scenarios.

Access to more sophisticated types of radiology (for example, MRI scans or nuclear medicine) is currently much more limited, with larger centres more likely to provide these as a 7-day service.

The committee noted that the provision of a 7-day diagnostic service has been identified by NHS England²² as being crucial to all elements of patient care and that the Royal College of Radiologists has produced standards for providing a 7-day service.³⁰ Furthermore, there is existing NICE guidance on acute medical emergencies within specific medical conditions that would require a 7-day diagnostic service to be present. This includes guidance on:

• The diagnosis of stroke, which recommends the use of brain imaging within the next available ‘slot’ and definitely within 1 hour, whichever is sooner.¹⁹
• The diagnosis of head injury in adults, which recommends a CT head scan within 1 hour of a high risk factor being identified.¹⁸
• The diagnosis of deep vein thrombosis, which recommends a proximal leg vein ultrasound within 1 hour in patients with a likely 2-level DVT Wells score, or within 24 hours coupled with interim 24 hour dose of a parenteral anticoagulant if ultrasound is unavailable.¹⁷

The committee considered that immediate access to CT is also needed for other acute medical emergencies, such as thoracic dissection or pulmonary embolus. Rather than recommend research into the effectiveness of 7 day diagnostic radiology compared to no such provision the committee wished to target the research recommendation towards examining what a service supporting 7 day care would be comprised of.

NHS radiology services have already made significant moves towards a 7 day service in recent times particularly in terms of diagnostic radiology provision. The committee noted that access to 7-day radiology encompassed access to the equipment as well as access to a person specialised in interpreting the result. They noted that there were some diagnostic radiological investigations for which consultants in non-radiological specialities were sufficiently skilled to provide an interpretation, for example, plain film chest x-rays, whilst MRI and CT would require special expertise.

Remote (tele-interpretation) reporting would be possible and could be cost-effective, for example, interpretation from overseas during the night. There are case studies on the NHS England 7 day services website of centres providing 7 day imaging services for CT, MRI and ultrasound including some elective outpatient work at weekends. However, there would be occasions where direct interaction between clinician and radiologist would be needed and could provide added value.

There is growing interest in computer-aided detection and diagnosis from radiological images. Were this approach to demonstrate an accuracy comparable to that of an expert radiologist, the potential impact on service delivery should also be evaluated.

Interventional radiology is a more complex service to provide. The Royal College of Radiology (RCR)³⁰ has provided guidance in the document produced by the Academy of Medical Royal Colleges on acute interventional radiology services. It is not possible, practical or affordable to offer such high-level services on all hospital sites.

Networks or hub-and-spoke solutions may provide the services that are needed. Both require the movement of potentially acutely unwell patients. The interventional radiologist workforce would need to grow to provide this service throughout England.

The Royal College of Radiology has already issued standards and guidance for delivering services:

• Standards for providing a 24 hour diagnostic radiology service.²⁹
• Standards for providing a 24 hour interventional radiology service.²⁸
• Seven-day consultant present care implementation considerations.¹

The committee were aware that the provision of a 7-day radiological service may have a substantial cost implication. Therefore, they considered it to be important that any research into the components listed above be conducted with an analysis of cost-effectiveness.

The committee were aware of reports from the National Imaging Clinical Advisory Group²⁰ and Scottish Clinical Imaging Network²⁷ on 7 day working in imaging that are available.