In the UK, with healthcare being free at the point of service, it’s easy to imagine that there are no barriers to access. What are the other barriers to healthcare?
I realized that people don’t usually deliberately present late – mostly they don’t know what they should be looking out for. Also, if they are just a bit worried that something is not quite right, it’s actually quite hard to get an appointment with the GP. Also if you are in a low-paid job and you take half a day off to go the GP, you lose half a day’s pay, which is in itself quite a barrier to going to the GP. So that was where the idea behind the Man Van came from – in fact, Johnny himself had presented late, despite realizing that he needed to go to the GP but he’d struggled to get access and ended up presenting via A&E [the Accident and Emergency department] with the cancer that eventually killed him. The current model for cancer diagnosis is that you have to: first, figure out that you have a problem; second, get a GP appointment in an area that is likely to be underserved by GPs; and third, get referred to a specialist. This system is loaded against those in lower socio-economic groups, those with lower literacy and non-native English speakers. There’s a lot of data showing that deprivation is a determinant of (healthy) life expectancy and that ethnic minority groups are disproportionately affected by deprivation.
What is the rationale/evidence for screening an asymptomatic population and how does your Man Van testing fit into the usual healthcare pathway? Testing for prostate specific antigen (PSA) is the only biomarker test we have for prostate cancer currently. We don’t have systematic PSA screening because of the generic problems that affect all screening – a certain proportion of people with abnormal results will have the disease (true positives) but a certain proportion will have raised PSA levels but no cancer – false positives. This leads to overdiagnosis and overtreatment. Also, there will be some people with normal results who will actually have prostate cancer (false negatives), who are then given false reassurance.
So, now, if you have a raised PSA result, you are referred for an MRI scan, and in our clinic approximately half of the patients are found to have no problems and need no further investigations, which helps to rule out overdiagnosis and MRI is a good tool for monitoring so that helps to reduce overtreatment as well.
Although we don’t have systematic PSA screening, men over 50 years old can go to their GP and request a PSA test (known as the Informed Choice programme). What happens is that people in the least deprived quintile of the population are much more likely to request a PSA test than men in the most deprived quintile. So the current programme of having to try to decide for yourself whether you are at risk or not is biased in favour of the people least at risk of presenting late. The most deprived group has a 14% higher mortality rate and a 29% higher risk of presenting with metastatic disease than the least deprived group. Delayed diagnosis is a key cause of these outcomes.
There’s actually very little data on whether you should do mobile testing for prostate cancer. However, our hypothesis was that mobile outreach clinics (the Man Van) are an effective mode of targeted testing, early detection and diagnosis of prostate cancer among ethnic minorities and deprived populations, being cost-effective and combining point-of-care (POC) blood testing with the assessment and diagnosis of other important health issues .
How did you find the patients to recruit into the Man Van?
We tried a variety of community engagement routes to access our target population (local council’s health commissioner, local churches and mosques, local radio, and community groups. All of these things helped, but in the end the best way was to park the van outside GP surgeries and we got the GPs to send texts to all their male patients, and this generated the most traffic. The GPs were actually pretty keen and supportive because we were doing health checks that were an extension to their own practice but we were avoiding burdening them with prostate cancer checks.
How have you been assessing how effective the project is and what have the results been so far?
In terms of reaching our target population, our pilot study results showed that almost exactly 50% of our patients were non-white and, particularly significantly, black patients were over-represented by a factor of almost two. Hence, the methods we used for reaching our target population worked very well.
In terms of detecting prostate cancer, we found that we detected double the number of prostate cancers that would be found if we just screened everyone over 50, which shows the effectiveness of the strategy. We are still not sure why we have this increase in detection rate, but it might be due to people coming to see us who have strong family histories of prostate cancer.
Additionally, we picked up a lot of other health problems, which included hypertension, diabetes, pre-diabetes, urinary referrals as well as obesity and, in lower numbers, excess alcohol consumption, smoking and mental health issues.
In terms of research, the other POC testing that we are doing is also to understand more about the acceptability of polygenic risk scores to patients and clinicians using the mobile outreach clinics and to develop risk score calculator based on the polygenic risk score, ethnicity and family history to stratify patients for prostate cancer risk. We know already that the lifetime risk of developing prostate cancer based on polygenic risk scores is higher for men of African heritage than for men of European heritage. We have just started some research where we are taking a saliva sample and profiling people’s DNA and then inviting people in the top 10% of risk for further investigation with an MRI scan.
Has your method of operating the Man Van testing evolved while you have been running the project?
Regarding our POC testing for PSA, the test takes around 15 minutes, and appointments were timed for 15–20 minutes. What we found was that most of the raised PSA results were only slightly raised and fell within the margin of error of the POC device meaning that the PSA levels of a lot of people with results just above or below the cut-off level of the test could not be accurately designated as positive or negative. The other problem was the for people with clearly raised PSA levels, we didn’t have enough time in the appointment schedule for a delivering the news of a cancer diagnosis. So the only way that we thought we could use this system as a POC test was to dual test, and to follow up the initial POC test with a confirmatory lab test. However, this would have meant sending some people away unnecessarily worried, or having to get some people back who had thought that they were OK. So we decided to move away from the POC test and to use the lab-based blood test. Then patients are then sent a text message if the levels are normal or followed up with a telephone appointment (which they are warned is going to happen) if the levels are in the abnormal range to discuss what this means and the patients end that discussion with an appointment for an MRI scan. This approach was the most efficient for the workflow.
For the HbA1C test, we also ended up moving to the standard lab-based test on the venous blood sample, as there were difficulties ensuring the accuracy of the POC device in a mobile unit – particularly with regards to temperature fluctuation. Again then the results were relayed to the patient (clear, pre-diabetic, diabetic) and given to the GP. Although we have moved away from POC testing, we do know of other people running mobile testing units who persevere with the diagnostic uncertainty.
What do you envisage for the future of the project?
Our present project finishes in January . NHS England are running a series of pilot projects on health inequality – another Man Van in Manchester (UK), and schemes at GP surgeries to send out targeted invitations – and they will analyse the results from all of these projects to come up with recommendations for the health minister, which may take up to a year. We, of course, are analysing all of our data, which we will publish and make our own recommendations. In the meantime, we are hopeful that we can come up with the funding independently from NHS England to carry on doing this in the interim in some way, shape or form, because there are multiple strands to the work – in terms of our research on the polygenic risk score, and raising awareness, as well as being a health service for underserved populations, providing equality of access. I’m optimistic that it provides a model to address inequality in healthcare access more broadly. We’re also looking to expand the system to targeted referrals of CT scans for people who smoke to catch lung cancer early, as well as handing out fecal occult blood test kits for patient groups who should have been offered bowel cancer screening but perhaps are less likely to have taken up the opportunity. So there’s a lot we can do and I hope we can continue with it.