Merry Christmas everyone!
I was in a room with the National Programme Manager earlier this month. It wasn't a hotel room or a police cell, but it was both relaxing and arresting, and gave rise to some interesting questions. Not all of which have answers. Amongst these was the issue of whether or not we should consider using a single field of view for screening, rather than the two we currently employ, and having posed that question, Lynne Lacey stated that the HTA have reported very similar sensitivity and specificity for the detection of sight-threatening diabetic retinopathy (STDR) with just one 45º view.
When she said HTA, I'm assuming Lynne meant the Health Technology Assessment Programme and not the Horticultural Trades Association, although as we're talking about fields, I could be wrong. The former is part of the National Institute of Health Research, and "produces independent research information about the effectiveness, costs and broader impact of healthcare treatments and tests for those who plan, provide or receive care in the NHS". Which covers virtually all of us, and makes their views well worth a listen.
The NHS Diabetic Eye Screening Programme in England has always employed two 45º fields of view, one centred on the macula and the other on the optic disc, and to anyone familiar with this method, the suggestion of reducing our field of vision to a single photograph of each eye seems entirely counter-intuitive. Two images must be better than one. The more of the retina we can see, the more chance we have of spotting STDR, the more accurate our grading will be, and the less likely we are to miss something serious. We've all come across examples like this...
The temporal view shows, at worst, mild R2, but the nasal view reveals active new vessels. Relying on the first image alone would result in a routine referral, when an urgent one is clearly needed. With a bit of digging, I could probably find a macula-centred view which looks like a minor case of R1, complete with a disc-centred shot of R3. So it's case closed, surely? We need that second field.
Well, I'm not so certain. Back in 2004, the British Journal of Ophthalmology published this study from a team in Scotland which aimed to assess the effects of single versus three (rather than just two) field photography on screening for diabetic eye disease, and the results were somewhat startling. They concluded that using mydriasis and three field photography does not increase the sensitivity or specificity of detecting diabetic retinopathy. In other words, taking one photo without eye drops produces results which are just as accurate as those you'd get if you dilated the patient and took three photos of each eye. It might seem counter-intuitive, but it's peer-reviewed and in print.
Following on from this study, the Scottish Diabetic Retinopathy Screening Programme opted to go with single field photography, which it still employs to this day. In England we've always used two-field photography, but by putting this issue firmly on the agenda, Lynne Lacey has (quite rightly, in my opinion) started a debate which could have far-reaching consequences for the national programme. Put simply, this is a potential game-changer.
I spoke recently to a retinal screener from another programme who was telling me about the steady increase in her workload, and said that in order to meet the rising demand for screening without any increase in budget, she's being asked to screen almost forty patients a day. That includes measuring the visual acuity, dilating the pupils, recording any notes and taking the photographs. And she's not alone. Every screening programme in England is seeing its patient cohort grow year upon year, but I don't know of any with a rising budget to match. Programmes are consistently being asked to do more for less, and with that situation likely to continue, it's inevitable that the number of patients seen by each screener in clinic will have to go up.
As a retinal screener, that gives me concerns for my colleagues across the country, but equally I fear for the patients. The more people we see in each clinic, the less of a service they get. As patient numbers grow and appointment times shrink, the educational nature of the job will all but vanish, as the time to talk to patients becomes a luxury that no one can afford. Patients will end up being herded in and out of clinics by stressed, over-worked screeners who barely have the time to check a date of birth, never mind discuss a patient's condition. Photographs will be captured, but the quality of patient care will be diminished beyond recognition. All those added extras - the education, information and friendly, personal service that can transform a simple screening appointment into something far more valuable for the patient and just as rewarding for the screener - well, all of that will be lost.
Adopting a single field strategy would change that overnight. Taking only one photograph of each eye would dramatically reduce the need for drops, and with tropicamide priced at around 50p an ampoule, that would instantly slash costs. Removing the need for dilation, and halving the number of photos taken, would speed up the practicalities of the screening process and give the screener more time for patient education and feedback, while the likelihood of not having drops would encourage patients to attend, and reduce DNA rates. Meanwhile, back in the office, graders would have half the number of images to assess, and could potentially grade twice as many patients. Capacity would increase, as would patient uptake, and yet costs would realistically go down.
But what about the patient above? How do we manage the risk of an R3 patient masquerading as an R1 in a single temporal view?
Well, it's quite simple. We adopt a halfway house between single field and two-field photography. A few months ago, I mentioned that our national number-cruncher, Strat the Stat, had come to the conclusion that annual screening for patients with no retinopathy might be a waste of our resources. Well, so is two-field photography. And probably mydriasis too. I would implement a very simple new rule: all patients are subjected to single field retinal photography until such time as they have background retinopathy in both eyes. At that point, they're put on an annual rescreen and given two-field photography at future visits.
Adopting this rule would result in the overwhelming majority of patients being effectively screened with just a single photograph of each eye, whilst simultaneously ensuring that anyone at any risk of STDR gets a two-field screening. As technology advances, and cameras improve, more and more of those single field screenings will be possible without drops, and by limiting this method to those patients at lower risk, we can rest assured we're not missing anything, whilst successfully reducing costs.
Put it this way: in front of you is a patient with type 2 diabetes. They're diet-controlled, and received a grade of R0 at their last screening, twelve months ago. With your budget increasingly tight and your workload rising, do you really need to spend significant time and money dilating their pupils with tropicamide and capturing four distinct views in an unlikely search for sight-threatening diabetic retinopathy, or would one undilated photo of each eye suffice? I'd suggest that's one question which does have an answer.
One of the trickier challenges for any diabetic eye screening programme is getting the wording right on the patient letters. Communicating the potential seriousness of diabetic retinopathy without terrifying the patient in the process is a balancing act that would challenge the skills of Charles Blondin, and when you add in the need to be clear and concise enough to earn a crystal mark, the feat becomes nigh on impossible.
Where I come from, Crystal Mark is the rough-looking bloke down the road who's addicted to methamphetamine, but in other parts of the country it's a highly prized award from the Plain English Campaign, which can be earned by any document with the clarity of a freshly fitted lens implant. The Derbyshire Diabetic Eye Screening Service won an even more prestigious award earlier this year, which was somewhat surprising as most of their letters begin with the words "Ey-up, duck", and they use the phrase "dunna wittle" in their R1 results.
But for the rest of us, finding the right words can be a constant struggle. A number of years ago, we started getting phone calls from patients who'd been told they had background retinopathy and were worried they were going blind. So we added a line to the results letter stating "This does not mean you are going blind". At which point we started getting calls from people who'd never even thought about losing their sight, and were suddenly terrified by the word 'blind'.
To this day, about 50% of newly diagnosed R1 patients tell me how reassured they were by the wording of our results letter. The other 50% tell me how panicked they were. The concept of Ironic Process Theory states that if you tell people not to think of an elephant, they automatically do. Except that in this case, half of them think of Dumbo, while the others think of the killer elephant attacks they've watched on YouTube.
To my mind, one of the main aims of patient letters should be the avoidance of telephone calls. Any letter which prompts either a question or a fear is going to result in a call to the office to have those questions answered and those fears allayed. An imperfect letter template could mean an entire admin team being tied up indefinitely. And yet getting it right seems extraordinarily difficult. When a patient moves into our area from another screening programme, they often bring their last results letter with them, and I'm constantly amazed by the variations in wording. A recent example informed the patient that whilst his eyes were clear of diabetic retinopathy, they'd noted an unspecified "non diabetes related issue" which might require treatment, and urged him to contact his GP. As far as the patient was concerned, it could have been anything from cancer to a brain tumour. It turned out to be a cataract.
Unfortunately, when it comes to clear communication, the national programme fares no better. The 'Guide to Diabetic Eye Screening' that we're all handing out to the patients, lists the concepts of 'bringing your glasses' and 'not driving after the appointment' under "hints and tips" rather than vital information. Which is a bit like putting the appointment time as a P.S..
And as for the national letter templates, they're an object lesson in the difficulty of getting it right. Logging on to the DESP extranet provides you with access to twenty-one standard letter templates, covering almost every eventuality bar alien invasion and tsunami, and yet still the perfect wording proves elusive. Take the R0M0 results letter. This is the one that all patients dream of getting, sent to those with no retinopathy, who have nothing to worry about and no problems to fear. It's the medical equivalent of a missive from the Reader's Digest prize draw manager. And here's how it breaks the good news:
You are at very little risk of sight-threatening diabetic retinopathy at this time.
Hurrah! A small risk of blindness! At the moment! It goes on...
Screening detects nearly all early signs of diabetic eye disease. However, very occasionally it can miss changes that could threaten your sight.
So we've probably missed something terrible. But we'll see you again in a year. Although whether you'll have enough vision left to see us is another matter.
That letter should fill people with happiness, relief and positivity, not fear, dread and paranoia. Unfortunately, the only people benefiting from that particular wording are the opticians with fundus cameras who can charge our worried R0M0 patients for an unneeded extra test.
Of course, the results letters are always going to be a minefield. But the appointment letters should be plain sailing. And plainly worded. Or so you might think. The standard DESP invitation letter template, which can be downloaded from the extranet, suggests using the following text:
The aim of diabetic eye screening is to detect any changes caused by diabetes that could damage your sight. You may be completely unaware of these changes but they are usually very treatable.
I like that wording a lot. The second sentence in particular sums up the most important, and most reassuring, aspect of screening: that if we find problems, we can treat them. It's something we need to repeat ad infinitum, in appointment letters, results letters and in clinics. It's the one fact that can stop patients worrying, and - despite its apparent obviousness - it's not widely enough known. This time last year, we added that text to our appointment letters, and it seems to have worked well.
Until now, that is.
I screened a Middle Eastern gentleman this week, whose knowledge of English was limited, but probably better than the average EDL member. Despite having to speak a little slower, we understood each other perfectly, and his affable nature meant that by the end of the appointment we were firm friends. I concluded by showing him the retinal photographs, talking him through what I could see, and reassuring him about the likely outcome, before standing up to show him to the door.
At which point he looked very confused. I repeated the information, briefly, in simpler words, but he still looked decidedly puzzled. So I asked him if he had any questions. His response succeeded only in transferring that look of confusion from his face to mine.
As unlikely as it may sound, he asked me why the appointment letter had told him to bring a change of clothes. I replied that it had merely asked him to bring a pair of glasses, but he was adamant that he'd been expecting to take all his clothes off, and wondered why I'd let him keep them on, suggesting that maybe I hadn't done my job properly. I politely argued my point again, and he responded by producing his letter and directing me to the section concerned.
It transpired that he'd taken the phrase "You may be completely unaware of these changes" to mean "You may need a complete change of underwear". He then held up a bag containing a pair of pants and a vest. And he wasn't even joking.
I'm not sure which is more surprising: the fact that he'd misinterpreted our letter so spectacularly, or the fact that he was quite happy to go along with it. Let's face it, if anyone has a good excuse for a DNA, it's the man who thinks the screening process involves getting naked, and may very well soil your underwear.
I can't wait to hear what he thinks of our results letter. He'll probably read 'background' as 'backside' and complain that I refused to look at his bottom.
With 2013 now upon us, and the Mayas looking sheepish, perhaps the biggest threat to the future of the NHS Diabetic Eye Screening Programme is our failure to restructure our screening intervals. Back at the dawn of civilisation (circa 2003), it was decided that diabetic retinopathy screening in the UK should adopt a 'one size fits all' approach, which is unfortunate, as it's a phrase which strikes fear into the hearts of a lot of type 2 diabetics with body image issues. As a result, patients found to have sight-threatening DR are referred to the hospital eye service, while everyone else is screened annually, regardless of potential risk.
As patient numbers increase, and budgets are squeezed, the need to look again at this policy has become ever more important. On the one hand we have those diet-controlled octogenarians who claim they were only diagnosed with diabetes because they ate a Chocolate Hob-nob ten minutes before having a blood test - and then prove it by coming back year after year with no retinopathy - and on the other, we have the young type 1s with bad control and a bit of background, who can go downhill faster than Rik Waller on a log flume. Yet we continue to screen them all annually as if there were no distinction.
The less money we have, the more crucial it is that those scarce resources are targeted appropriately, and it's long been suggested that to screen patients with no retinopathy on an annual basis is a waste of our time and money. Conversely, we need to ensure that those patients who have the potential to progress on to sight-threatening DR are not left too long between screenings.
The solution, it would seem, is to identify those patients at low risk, screen them less frequently, and channel those extra resources into more frequent screening for those at higher risk. It's a simple and sensible solution, makes sound financial sense, and seems a lot better for all concerned. Assuming you know who they are.
The problem is identifying which patients fall into which group. And that was the aim of a recent study carried out by Irene M Stratton (the M is for Maculopathy), senior statistician of the Gloucestershire Diabetic Retinopathy Research Group. I've a lot of respect for Irene. She's a vastly experienced number-cruncher with some head-turning vital statistics, and she's produced more funnel plots than a conspiracy theorist. I also like the way she seems to be turning the word 'Stratification' into an eponym.
The important thing is that Irene has a very attractive figure. And that figure is 14,554. It's the number of patient outcomes she's studied in order to develop a simple algorithm to assess the risk of a patient screened annually for diabetic retinopathy developing sight-threatening DR within that twelve month period. You can read more about Irene's stratifications by clicking here, but it's the conclusions which are interesting, and more than a little surprising.
The aim was to estimate a patient's future risk by looking at the results of two consecutive eye screenings. And here's what she found:
Of 7,246 with no DR at either screening, 120 progressed to sight-threatening diabetic retinopathy (STDR), equivalent to an annual rate of 0.7%.
Of 1,778 with no DR in either eye at first screening and in one eye at second screening, 80 progressed to STDR, equivalent to an annual rate of 1.9%
Of 1,159 with background DR in both eyes at both screenings, 299 progressed to STDR, equivalent to an annual rate of 11%.
A lot of attention has been focused on that final statistic, but I find the first one just as shocking. I'd like to know what went on in the lives of those 120 people who had R0 for two years running, and then went straight to M1 (or possibly R2?). And more to the point, who was responsible for their care? Or lack thereof.
The implication is that patients who have no retinopathy for two consecutive screenings can probably be left for a couple of years, although I wouldn't like to be the one who has to explain that policy to an anxious individual who reads the figures above, and points out that one such patient in every 150 will go blind before their next visit.
That aside, it would appear that anyone found to have background retinopathy in both eyes on two consecutive screenings has a better than 1 in 10 chance of developing STDR within twelve months, and therefore needs to be screened more often. But is that the full picture?
My suggestion is no. I think this is:
That eye has received an official, undisputed, and quality assured grade of R1M0, meaning it has background retinopathy with no maculopathy.
And so has this one:
That's not a doctored photo, it's a genuine case of R1. There's a faint microaneurysm less than two disc diameters from the fovea, on the temporal side.
Does it seem likely that the first patient could progress on to sight-threatening DR within the next twelve months? Absolutely. But what about the second?
The problem is that just as the current system makes no distinction between a low risk type 2 with no retinopathy, and a high risk type 1 with background, a system based purely on consecutive grades of R1 would make no distinction between the two patients above. If the second patient came back a year later with the same microaneurysm, they'd be classed as high risk, and called back in six months. Which, on an instinctive level at least, doesn't seem like the best use of our resources.
I'm all for simplicity, but perhaps screening grades alone are unreliable. Perhaps we need to include factors such as whether the patient is type 1 or type 2, whether they're diet controlled or on medication, and how long they've been diabetic. Maybe we even include their latest HbA1c and take their blood pressure.
Or maybe we just redefine R1. A grade which covers both the patients above, and everyone in between, seems far too wide to be meaningful. Especially if we're considering using it to judge future screening intervals. But in these times of austerity and increasing workloads, there's no doubt the system needs reform. Perhaps desperate times call for DESP E-Rate measures.
