The justification of non-obstetric ultrasound referrals: A safe and effective practice

Abstract

Introduction

In 2015 the British Medical Ultrasound Society released a referral justification document for rejection of inappropriate ultrasound referrals to help manage increasing demand and ensure correct utilisation of diagnostic imaging tests. In our trust, referrals that were not aligned with the guidance were cancelled and returned to general practitioners, providing reasons for cancellation and advising other diagnostic tests if appropriate.

Methodology: In total, 1000 cases cancelled between April and August 2019 were retrospectively audited by a team of clinical specialist sonographers. Interoperator agreement against BMUS justification guidelines and safety of this cancellation process were established. Duplicate imaging referrals, referrals made that should have been placed on management pathways or referrals cancelled by the patient directly were excluded in the safety assessment.

Results

There was strong agreement amongst sonographers regarding cancellations. After exclusions, 389 cases were included for review. The majority (90.5%) required no onward imaging and were therefore deemed cancelled appropriately. There were 37 patients found with pathology on subsequent imaging, two of which were found to have cancer and the remainder with benign pathology.

Conclusions

Overall, we found the cancellation process to be safe and the justification document easy to utilise in practice. This process has ensured a minimal waiting time for ultrasound imaging is maintained and that demand can be managed to meet the available capacity.

Introduction

Demand for non-obstetric ultrasound examinations has seen an exponential increase over the past decade. From 2014 to 2019, imaging activity for all diagnostic modalities has increased by 26%. The largest increases are seen in CT and MRI (38% and 29% respectively), closely followed by ultrasound (20%). ¹ This increased demand may be attributed to clinicians becoming more reliant on imaging to aid clinical judgement with life expectancy increasing and more patients living with chronic conditions requiring monitoring. ² , ³ Furthermore, reduced appointment times and shortages of general practitioners (GPs), in addition to the restrictions in place due to the COVID-19 pandemic, are likely to have resulted in practitioners in primary care not having adequate time to clinically assess patients. ⁴ There is also evidence from the recent 2020 Getting It Right First Time (GIRFT) report in radiology that ‘sometimes clinicians request a full set of imaging modalities because they are unsure what will actually be provided swiftly to enable their diagnosis’. ⁵ Combined with emergent defensive practice to avoid medico-legal action, this has led to further increases in the numbers of unnecessary referrals. ⁴ , ⁶ Requests generated in this manner pose little clinical worth, ⁶ but add pressure on ultrasound departments across the country, amplified by vacancy rates for sonography being at 12.6%. ⁷ , ⁸

Although activity growth for ultrasound has been less than CT and MRI, ultrasound was the second most commonly requested diagnostic examination by GPs between 2018 and 2019, with 10.2 million referrals generated annually. ¹ Pressures are set to increase with the NHS Long Term Plan, ⁹ which has ambitions pledging to improve long-term cancer outcomes over the next decade by increasing early cancer detection at stages 1 and 2 in 75% of people. Demand for fast access diagnostic ultrasound is predicted to surge by 25%. ³ Data are based on direct access referrals alone; activity data for secondary care in-patient, out-patient and obstetric referrals are under-researched. Anecdotally, our institution saw an increase in obstetric demand of almost 50% since 2016, as the Saving Babies Lives care bundles version 1 and 2 were introduced, highlighting the ever-growing issues surrounding capacity, demand and staffing pressures.

Studies have found imaging services are overused by GPs, with up to 40% of investigations being unnecessary ² , ¹⁰ The resultant increase in incidental findings generates further unrequired investigation. ¹¹ Over imaging, repeat imaging, incorrect modality and unnecessary investigations all contribute to inappropriate use of imaging resources. ¹² This results in financial and capacity burden thereby reducing imaging turn-around times. ² , ¹⁰ , ¹³ , ¹⁴

Evidence suggests referrals are often made without a true imposed clinical question. ¹² Referrers have a responsibility to provide adequate information for practitioners to make informed decisions about pathological findings. ¹² , ¹⁵ This is particularly important from a medico-legal perspective, as referrers can be held accountable if pathology is missed due to insufficient clinical information. ¹⁵ A good referral should contain symptomology, history, pertinent previous imaging and laboratory investigation results, yet in practice this is infrequently observed. ¹⁶ Imaging referrals should be evidence based, yet studies have found GPs refer following information from non-evidence based resources and Google ©. ¹⁷

In 2015, the British Medical Ultrasound Society (BMUS) released a guidance document for primary care referrers – “BMUS recommended good practice guidelines – justification of ultrasound requests” – which outlines the referral criteria that are most suitable for an ultrasound examination. ¹⁸ There is a wealth of evidence to show that certain diagnostic tests are better for diagnosing specific pathology, e.g. ultrasound is superior for managing gallstone disease, whereas CT is better for diagnosing pancreatitis. ¹⁹ The BMUS document was produced to ensure patients receive the correct diagnostic test first time, thereby reducing delays in diagnosis and treatment. ¹⁸

In 2017, following consultation and agreement from the local Clinical Commissioning Group (CCG), our institution implemented a modified version of the BMUS guidelines. We began a process of cancelling requests without a suitable clinical question, or where ultrasound would not be suitable. The process involved cancelling all direct access referrals which were not in line with the locally agreed BMUS document. ¹⁸ Any referrals which were not justified under the agreed guidance were ordered onto the radiology information system (RIS) as the original examination requested, with an added RCANCEL RIS code attached. These were subsequently reported by a sonographer within the ultrasound department and the report returned to the referrer. The report provided guidance on what information would be required to justify the referral or advice about which imaging modality would be more suitable based on the clinical details provided on the original request. This method enables inappropriate referrals to be identified on RIS using the RCANCEL code for the purposes of audit and transparency.

Prior to implementing this process, the demand for US imaging increased by 14.6% in 2016–2017; following implementation, demand decreased by 1.3% in 2017–2018. There was a subsequent increase of 5.7% in 2018–2019, but this is significantly lower than projected without this intervention. Prior to implementation, GPs were informed of this change in pathway via the local pathways review committee of the CCG.

March 2020 saw the Coronavirus-19 (COVID-19) crisis result in immediate cessation of all diagnostic activity that was not deemed clinically urgent. ²⁰ The number of ultrasound examinations performed reduced significantly and our institution saw a decrease in GP referrals for ultrasound scans. This led our service to question whether resources were being used adequately pre-COVID-19. The COVID-19 pandemic highlighted that whilst there is a process in place locally to manage demand, the safety and effectiveness of this process had not previously been reviewed. Anecdotally, there is awareness that clinicians have concerns about not imaging patients and that diseases are going to be missed, resulting in continued inappropriate referrals being received, despite clear guidelines and feedback for referrers. Whilst the 2020 GIRFT report for radiology wholly supports the principle of GP direct access for imaging, it also advocates that imaging should be used appropriately within patient pathways. ⁵ The report recommends the use of agreed, consistent, clear and standardised imaging referral guidelines which aid the referrer and assist in managing demand. To date, there are no data available for rejection rates. ⁵ This single-centre audit is designed to better understand the locally agreed justification process and assess its safety and efficacy.

Aim

The aim of the audit is to evaluate the local process of managing inappropriate referrals. A secondary aim is to determine if patients have come to significant harm, or had treatment delays, due to the implementation of the local justification process.

Method

A retrospective audit of 1000 referrals received between April and August 2019 which had been cancelled using the locally agreed radiology cancelation process (RCANCEL) was undertaken. This constituted approximately 30% of all referrals cancelled in the year 2019–2020. A team of clinical specialist sonographers reviewed the 1000 cancelled cases, noting the original reason for cancellation and whether the reviewer agreed with the original reason for the cancellation in line with the locally agreed BMUS guidance. The reviewer referred to the locally agreed guidelines as the standard to assess validity of cancellation. The imaging history of each case was reviewed to determine if the patient had undergone a further imaging investigation following the cancellation, and if so, the modality used was noted along with the updated clinical details. The details were assessed to determine if they were similar to those of the original referral and therefore deemed to be relevant to the original presentation. If the request details were similar, the time frame between requests was noted and the subsequent radiology report reviewed to determine if any significant pathology had been identified. Those who had not re-presented with further/worsening clinical symptoms were deemed to have been appropriately cancelled. None of the 1000 cases were second reviewed to assess for interoperator agreement, which is a recognised limitation of this study.

A table of data was collated and presented on Microsoft excel. Reasons for initial cancellation of the examination are described in Table 1.

Table 1.

Predetermined cancellation reasons.

Abdominal mass (CT required)

Suspected groin hernia (not indicated locally)

Inappropriate PMB referral/non electronic referral

Incidental finding of a thyroid nodule (not indicated locally)

Bloating as the only symptom (more information required)

Suspected lipoma/ganglion (more information required)

Examination cancelled by the patient

Vague symptoms with no clinical question (more information required)

Duplicate referral (more information required to justify repeat imaging)

Suspected lymph node pathology (specific pathway required)

Patient discharged (more information required to ascertain if imaging still indicated)

Other (reason specified)

Haematuria (specific pathway required)

Suspected PCOS (not indicated locally)

Suspected sebaceous cyst (more information required)

Abnormal LFTs (one episode of mild/moderate)

Pelvic pain (not indicated locally)

Suspected soft tissue mass (more information required)

Significant findings at subsequent imaging were subdivided into the categories described in Table 2.

Table 2.

Categorisation of findings at subsequent imaging.

Cancer
Findings requiring treatment/intervention
Findings requiring lifestyle changes
Other
No abnormality detected

Results

Interoperator agreement

A total of 22 sonographers were involved with the cancellation process with experience ranging from 12 months’ post-qualification to 30+ years. All cases were reviewed against the locally agreed BMUS guidance. It was noted that less-experienced sonographers provided cancellation reports for referrals that were either duplicate referrals, where the patients themselves had requested the referral be cancelled, or where there were clear pathways that the referrer should follow. The more experienced and senior sonographers provided cancellation reports based on their own clinical judgment and for the more questionable referral details. There was a 98% (n = 984) agreement rate between the reviewer and the original reporting sonographers, indicating that the BMUS guidance is reproducible with little variation in practice. Disagreement between the reviewer and the original reporting sonographers occurred in 2% (n = 16). These cases were all related to referrals with vague clinical details which the reviewer would have accepted. Of these 16, one case was found to have a significant cancer on subsequent imaging.

Referral source

Referrals cancelled were received from 87 different referral sources within the region reflecting the large geographical area that is covered by our institution. Of these referral sources, there was a wide range in the number of referrals rejected from each different source (1 to 97) with an average of 11 and median of 7. No data are available to evaluate the percentage of referrals sent to radiology per referral source; therefore, referral rate per institution is unknown. However, the referral source with the highest number and range of type of rejected referrals is the largest consortium GP practice in the region. As the referral rate is unknown, it is hard to determine whether this is a reflection of the need for education or because rejection rate is expected to be higher in a consortium with a larger patient throughput.

Referrals were entered into the RIS using the most appropriate national code.

Examination requested

The majority of rejected referrals were either musculoskeletal (MSK) (n = 253), requests for pelvic examination (n = 207) or for upper abdominal examinations (n = 206) although a wide range of examinations were requested and rejected. The high proportion of MSK and pelvic referrals rejected was due to the need for these referrals to follow pre-determined pathways as opposed to the clinical details being inappropriate. A need for education regarding referral streams is required.

Reasons for cancellation and study exclusions

Approximately 60% of referrals were cancelled for one of three reasons; the patient wished to cancel, the imaging referral was duplicate, or because the original referral was made on the incorrect pathway (n = 611; Figure 1).

Figure 1.

Common reasons for cancellation.

Of these 611, a large proportion of cancelled referrals (n= 390) were for patients who were already on a care bundle related pathway, e.g. due to symptoms of haematuria or post-menopausal bleeding (PMB) (see Figure 2). As examples of care bundle pathways, in our institution patients with either haematuria or PMB are placed on a two-week wait fail-safe pathway and therefore were excluded from the study data. Patients on an established musculoskeletal pathway were excluded as this cohort has assessment and primary treatment prior to ultrasound imaging and intervention; a clear management protocol is in place with imaging as a second-line investigation. These clear care bundle pathways negate the need for imaging as a first-line investigation, and therefore rejection of referrals is not due to interpretation of clinical indications. Directly on to the correct pathway is without risk of delayed diagnosis as the pathway protocols have imaging within if required. Management pathways are outlined in Figure 2.

Figure 2.

Patient management pathways.

Significantly missed cases

Of the remaining 389 cases, 90.5% had no follow-up imaging (n = 352) and were therefore deemed appropriately cancelled. There were 37 patients (9.5%) found with significant pathology on their subsequent imaging examinations. Of these, two had cancer and the remainder (n = 35) had benign pathology requiring treatment. Of the pathologies found requiring treatment, 18 were from patients requiring an initial physiotherapy assessment. Arguably pathology was not missed in these cases as these patients had been placed on a management pathway for treatment prior to ultrasound referral. There were nine patients who had findings on subsequent imaging, such as fatty liver, that indicated the need for lifestyle changes but no other intervention, and three patients were found to have diverticular disease as a cause of symptoms. This left five patients who required intervention/treatment following their second diagnostic investigation (Table 3).

Table 3.

Significant benign pathology requiring subsequent intervention or treatment.

Case	Clinical details on initial cancellation	Clinical details on subsequent referral	Ultrasound findings following subsequent imaging
1	Smooth nodule right side of the thyroid gland. Picked up on CT chest. Palpable lump. ENT suggest ultrasound.	Secondary care re-referral: Large incidental thyroid nodule on CT	Large BTA U3 nodule seen in the left thyroid lobe. (Thyroid lobectomy performed)
2	RUQ pain please assess for structural cause.	Right upper quadrant pain, tender to examine. Please rule out gallbladder pathology	Gallstones.
3	ALT 233. Normal ALP.	ALT 233. Normal ALP. Nil on viral or autoimmune screen? liver pathology	Fatty infiltration. Biphasic hepatic vein flow. Splenomegaly.
4	Lump in groin for6 weeks ? cause	Smooth 2 cm lump right groin. Increased in size from 1 cm over past month. Now painful. No source of local sepsis evident. No cough impulse? cause	Direct inguinal hernia
5	Generalised abdominal tenderness. Tender to deep palpation. BS+	Secondary care referral: Pt admitted with #NOF, developed a fever, tachycardia, hypotension, diffuse abdominal pain, distension, dilated bowel loops on X-ray, possible perforation	Mildly dilated large bowel down to the sigmoid colon but no clear evidence of mechanical obstruction, the appearances are most likely in keeping with colonic pseudoobstruction. Sigmoid colon demonstrates multiple diverticula with no thickening; appearance may represent early evolving acute diverticulitis. Clinical correlation is advised.

Cancer on re-referral

Of the 1000 cases rejected, two patients were diagnosed with cancer at subsequent imaging (Table 4). On review of these referrals, one case was rejected as an ultrasound referral as a referral for CT was also made and performed in preference. The second case was rejected as the vetting sonographer felt the clinical details were vague. The reviewer disagreed with this cancellation.

Table 4.

Referrals cancelled where cancer was reported on subsequent imaging.

Case	Clinical details on initial cancellation	Clinical details on re-referral	Ultrasound findings following re-referral
1	RUQ pain ? cause	Abnormal LFTs, weight loss, anaemia ? cause	US found intrahepatic duct dilatation. Second opinion from radiologist stated not believed to be significant. CT suggested finding cholangiocarcinoma. Disagreement between cancellers
2	Niggly right loin pain	Chronic upper abdominal pain ? cause (CT referral)	13 mm lesion lower pole of right kidney, characterized with CEUS as malignant lesion however patient is having conservative management

Delayed imaging

The aim of a robust justification process is to ensure patients receive the best test at the right time in their pathway. A rejection process should not significantly delay appropriate imaging. Of those patients who had subsequent imaging, either on the correct pathway or following a subsequent referral, 61% were imaged and reported within six weeks of receipt of the original referral being received. The longest wait was over six months for 14 patients and in one of these a small 13 mm renal malignancy was detected (Case 2; Table 4).

Discussion

Ever increasing demand for imaging

The demand for ultrasound imaging is ever increasing owing to a multifactorial picture. Mortality rate has declined over the past decade, yet health expectancy has not increased in a parallel fashion. ²¹ Evidence shows that in 2018 a British female lived an average of 83 years, yet 19 of them were spent unwell. ²² Increasing lifespan means increased risk of ailments and increased dependence on imaging for disease monitoring. Ultrasound has a staple role in monitoring chronic liver disease, with around 60,000 people living with cirrhosis requiring six monthly ultrasound monitoring. ²³ One in three people are predicted to have early non-alcoholic fatty liver disease, 5% of which go on to develop non-alcoholic steatohepatitis, and 20% of which will develop liver cirrhosis, ²⁴ highlighting the surplus demand placed on ultrasound services.

The burden from incidental findings is a growing phenomenon. ²⁵ Advancing resolution of machines allows detection of smaller lesions. ²⁶ CT chest, CT colonography and cardiac MRI have significantly increased detection of incidental findings. ²⁷ Only around 3% of incidental findings will require treatment/intervention, ²⁸ yet will generate a multitude of cross-modality imaging. For example, incidental finding of extrahepatic biliary dilatation or pancreatic duct dilatation generates a plethora of further examinations; CT, ultrasound, MRI, yet in non-jaundiced patients, false-negative rates across all modalities is low. Gold standard investigation should be endoscopic ultrasound yet 69% of findings are normal with 22% having benign pathology including lithiasis or chronic pancreatitis. ²⁸ In essence, justifying the referrals avoids unnecessary imaging for clinical indications where there is little or no benefit but where increased anxiety, due to the uncertainty of findings, may be caused. ²⁵

Causes of poor referrals

Poor understanding of imaging alongside defensive practice and GP appointment constraints result in an influx of unnecessary referrals with no imposed clinical question. ²⁹ Patient expectations, patient centred approach to medicine and appointment time constraints can lead to professional uncertainty, increasing the referral rate. ³⁰ Referrals are generated to demonstrate to patients that action is in progress with the aim of reducing medico-legal claims. These scans are of little clinical benefit but aim to prove high quality care if cases reach court. ⁶ Appointment constraints means that imaging referrals are substituting clinical examinations, causing increased dependence on radiology services. ² Imaging should be used as an adjunct to diagnose a clinical suspicion; however, tests are increasingly being performed and repeated where results are not expected to affect patient management. ¹⁶

Given that ultrasound is considered a safe and inexpensive imaging modality, it is often the first and easiest investigation for referral. Interestingly, despite the modern mind-set that imaging referrals will reduce patient anxiety in the presence of a negative result, ² the opposite has been found to be true in many studies. Long waiting lists allude to increased stress and many patients feel more frustrated when their symptoms cannot be explained, ³¹ with as many as 50% gaining no reassurance from a negative examination. ¹¹ This highlights the need for the correct examination to be requested based on clinical judgement in order to obtain an explanatory outcome for patient symptomology.

Why the need for a cancellation process?

Imaging resources must be used wisely to reduce economic resource burden and to reduce the burden on waiting times for imaging referrals. Half of all cancers are diagnosed late stage, with one-third of cancers diagnosed in people aged 75 or over. ³² Cancer waiting times are becoming increasingly more demanding; however, resources are not increasing exponentially. The year 2000 saw the introduction of the two-week wait diagnostics referral processes for suspected cancer to improve cancer detection times. ³³ Whilst this is likely to result in early intervention, it can cause increased patient anxiety, distress, unnecessary intervention and pressure on already stretched diagnostic services, and pressures are set to continue increasing. This route also requires GPs to have the knowledge to be able to order the correct test. ³²

This pressure is amplified by the fact that as many as 40% of referrals are unnecessary ² , ¹⁰ and that one-third of referrals are ‘consumed by the worried well’. ³⁴ Referrals need to be regulated to ensure examinations are not repeated when unnecessary and should only be done when findings are expected to alter patient care. ¹⁰ Report quality is directly proportional to referral quality. ¹⁴ , ¹⁸ Therefore, the need for a proper and clear clinical question is required to ensure the examination is justified and to ensure the correct examination is being performed in order to answer the imposed clinical question. This increased demand, and risk of reduced report quality, requires a pragmatic approach to utilize ultrasound resources more wisely. GPs often worry that patients who attend with vague symptoms will have significant pathology missed; however, our study has demonstrated the opposite to be true.

Limitations

Whilst a comprehensive audit of 1000 referrals has been made, there are limitations. First, the ultrasound referral was reviewed in isolation from the patient’s previous imaging history thereby limiting the information available to the reviewer that may have affected the reasoning of the sonographer undertaking the original review. Second, for the purpose of this study, GPs were not contacted to determine if the patients had undergone any other investigations in the independent sector or non-imaging investigations which provided reasoning for the patient’s initial complaints. This study deemed referrals as appropriately cancelled where no further imaging was undertaken within our establishment. Alternative diagnostic tests such as blood tests or scopes were not considered. As such, this study is subject to a degree of selection bias but the large cohort of referrals within this audit limit the influence of this and the results. Imaging performed by an independent sector provider was also not reviewed but no such providers exist in our locality. Furthermore, there has been no input from the referrers themselves as to why certain clinical details are provided. Engagement with primary care colleagues to improve the referral process is essential. Finally, this audit is limited to non-obstetric activity. A similar review of obstetric referrals is indicated if demand management within this ever expanding field is to be achieved.

This audit reviews referrals received and cancelled in 2019 when the majority of patients had face-to-face consultations. It has not evaluated the impact of telephone consultations upon the quality of diagnostic referrals, brought about by the COVID-19 pandemic. Subsequent audit to evaluate any change in referral practice is advocated.

Is the cancellation process safe?

Cancer was diagnosed at subsequent imaging in only two patients in this study following rejection of the initial referral. However, one of these referrals arguably should have been performed based on the BMUS guidelines. Overall, the rate of missed cancer in this study was 0.2%. Despite this delayed diagnosis, patient management was not affected (Case 2, Table 4). An ultrasound examination is effectively a screening tool for symptomatic patients. No test in medicine achieves 100% sensitivity and specificity although the aim of any test should be to reduce the false negative rate. Although not directly comparable, one in 2500 people have their disease missed within the current breast screening programme in the UK. Less than one per 100 screened women in the UK have cancer detected through breast screening alone and around 8 in 10 of these are invasive cancers. The breast screening programme is for asymptomatic patients and whilst general ultrasound examinations are performed for symptomatic patients, anecdotally these procedures are commonly used to screen the worried well. Whilst this audit has demonstrated that a cancellation process cannot mitigate against delayed diagnosis of significant disease, it is a safe process for managing precious resources. As demand for diagnostic imaging continues to rise, and pressures on capacity are unabated, particularly given constraints imposed by the COVID-19 pandemic, ³⁵ this cancellation process for managing referrals offers an effective process for ensuring patients receive the most appropriate imaging examination.

Conclusion

Justifying referrals to radiology relies heavily on the clinical information given by referrers. Resources are limited and the justification process is in place to ensure the best use of imaging service is provided. This audit has demonstrated that poor quality referrals can be managed effectively by rejecting them and offering advice and guidance to improve subsequent referral quality. This process has ensured a minimal waiting time for ultrasound imaging is maintained and that demand can be managed to meet the available capacity. Greater engagement with primary care colleagues to improve the quality of referrals is essential, thereby ensuring patients receive the right test within the correct pathway of care.

Recommendations for implementing a justification process

This study will assist departments to implement a safe referral justification process. Department-specific guidelines should be produced in conjunction with GPs, patient representatives, radiologists and departmental local guidelines in order to ensure robust guidance on trust specifics. We offer the following recommendations for service providers considering implementing a justification process to aid demand managements:

• A written agreed process for the management of referrals within the ultrasound service is required

• Clear, unambiguous, referral guidelines are required and should be locally agreed with the relevant stakeholders including referrers and service providers

• Appropriately experienced and accountable practitioners and commissioners should be involved with the justification process. Access to clinical support to assist with decision making for ambiguous referrals is required

• A peer review audit process should be in place to monitor consistency of rejection within the service

• The use of standard text replies to referrers, offering appropriate advice and guidance, is strongly recommended

• Subsequent audit to evaluate any change in referral practice as a result of telephone consultations due to the COVID-19 pandemic is advocated