Reducing contamination rates in urine samples: an interview with Prof. Frank Chinegwundoh MBE

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How much of a problem is contamination thought to be in urine sample collection?

Contamination is thought to be a significant problem. Depending on which study you look at, the rates of urine contamination can be 17% or upwards.

Doctor urine sample

Traditionally, what has been the standard method of midstream urine collection?

The standard method of midstream urine collection is for the healthcare professional to give the patient some sort of pot in which to collect their urine. Often, the pot is just given to the patient and they're told to produce a urine sample.

However, what should happen is that the patient should be asked to produce the midstream urine. In other words, not to collect the first bit of urine that comes out and not to wait until the very end, but to collect the bit in the middle.

Doing that involves the person starting to pass their urine and then holding it after a period of time, releasing the middle bit into a collecting pot and then removing the pot and completing urination.

That's difficult for most people to do. In effect, what happens is that if someone is asked to do a midstream urine sample, they start passing the urine, just pass the collecting pot across their stream to collect some and then pass it out again. Inevitably, you get urine down the side of the pot and often on your fingers. It's a bit messy.

What feedback do you get from patients on the standard method and how do healthcare professionals feel about it?

The feedback from patients is that they are embarrassed about handing the container back to the nurse or doctor because the outside of it is wet with their urine. They often try and wipe it down, which means you then can't write the patients details on the actual bottle because it's wet.

The healthcare professionals don't like to receive urine pots back that have got urine down the side because it's just unhygienic.

The patients don't like the standard method and neither do the healthcare professionals. I think, because of that, often what happens is that the patients just pass the initial bit of the urine into the bottle and then quickly move it out and we don't get a true midstream urine. I suspect that's what happens much of the time, which is why the contamination rate is so high.

Is it always midstream urine that needs to be collected or does it depend on what the urine is being tested for?

It depends on what you're testing the urine for. If you're testing the urine to see if there's infection or not, then the midstream urine is what you’re after.

If you're collecting the urine to see whether there's sugar or any blood cells in it, for example, then it doesn't have to be midstream urine; the patient can just pass urine as they wish.

Can you please give a brief overview of midstream urine collection system “Peezy” and why you decided to trial the device at the Royal London Hospital?

We decided to trial Peezy because I came across it some years ago at a conference and it struck me as being an ingenious way of getting a midstream urine without getting urine all over the bottle and also without the patients having to worry whether they are at the beginning of the stream, the middle or the end.

When I came across this device, I thought it would serve various purposes. Firstly, you would get a proper midstream urine. Secondly, it would be easier to collect the sample, especially for women who mostly sit down to pass the urine. Thirdly, you wouldn't get urine all over the collecting receptacle, which would be more hygienic for the patient and for the healthcare professional.

I thought it would be good to try this device and see if we could improve how the urine samples that are checked for infection are collected.

Our microbiologists found that approximately 17% of urine samples come back as being contaminated. The microbiology report would come back saying “scanty growth” or “mixed growth” and so on, whereas you want it to say either no growth or that there is growth of a particular organism, which is often E. coli.

We get comments such as “scanty growths,” “mixed growths,” and “mixed contaminants,” which means you don't know if there really was an infection there or not.

We thought we would look at, historically, how many urine samples going to the lab are deemed to be contaminated and see whether using this collecting device could reduce contamination, so we could get a better representation of what's actually happening within the bladder and whether there's infection or not.

What did the trial involve?

The trial is still ongoing. So far, we’ve looked at 66 urine samples and what we found was that the contamination rate was 1.5% compared to our historical contamination rate of 17%.

It's small numbers at the moment and we're hoping to get to a bigger sample size, of 200 specimens.

Certainly, the indication so far is that you get a better quality of urine sample and the microbiologist is better able to determine whether there's infection or not.

How much time did it take to explain how to use the device?

It does take some time, because with the traditional method of collecting urine samples, you just give the patient the pot and ask them to urinate in it. You may take a little bit more time to explain that it's the midstream urine you're after, but it's relatively quick.

With the Peezy, you do have to have a demonstration model and show how the collecting bottle attaches to the plastic funnel device. You do have to explain that when a person is passing urine into the funnel, they have to stand over a toilet, because the first part of urine is going to run through, the middle bit will be decanted off into a side channel to collect the midstream urine and then any excess urine will just go to the bottom.

You do have to spend some time explaining this to the patient because, for them, it's something completely different. If you do spend that time, which admittedly is a bit longer than when you just give someone a pot, it's worth it in terms of getting a decent sample and a clean collecting device.

It is important to take time to explain how to use the device. Unfortunately, I had one man who was a little upset when he came to see me in my consultant room, because he was given this new device to urinate into, but he didn't quite appreciate that he had to hold the device over the toilet.

I'm sure he was told and the nurse said she had told him but he actually held the device against his trouser leg and, of course, when he urinated into it, the first part of his urine went straight onto his trousers, the middle bit went into the test tube and the end bit also went on to his trousers.

It was only when he looked down afterwards that he realized what had happened. As a result, we've made sure to reiterate, especially to the men who stand up while using the device, that they make sure the funnel and the exit to the funnel are actually over the toilet.

Man peeing urinal

What other feedback did you receive from patients on Peezy?

The feedback has, for the most part, been positive. Since some patients said that they used it correctly, but not enough urine actually went into the side where the collecting bottle is attached, one of the things that we appreciate is that you need a fair volume of urine

for this Peezy device to work. Therefore, we now ask the patients to make sure that they've drunk sufficiently, so they can pass a decent volume of urine.

Most patients find it easy to use and they appreciate the cleanliness of the device. We did find that some patients had problems with it because they didn't pass enough urine or some patients with perhaps not as good manual dexterity as they would have wished, found it challenging to screw the test tube onto the Peezy device. A few had difficulty unscrewing the test tube and applying the cover to it.

The younger patients tended to find the device easier to use than some of the older ones, but, overall, the response from patients to this collecting device has been positive.

Also, some patients would comment that they don't have to worry about whether it's their midstream urine they're collecting; all they do is just urinate as they naturally would and the device collects the portion of the urine in the stream that we're interested in. In that respect, it takes the thinking out of it for the patient in terms of worrying about catching the midstream urine, as you have to with the old technique

In what ways do you think Peezy could be improved?

It's difficult to see how it could be improved. Perhaps for those people who lack hand dexterity, a simple push mechanism could be used rather than the screw top; pushing the test tube so that it clips onto the device.

Although, perhaps rather than improving the device, we should be asking our nurses to assemble the kit and hand it to the patient so that they don’t have to screw and unscrew the test tube.

What do you think the future holds for urine sample collection in general and at the Royal London Hospital?

I think that there should be a standard way of collecting urine samples. There are standard ways of collecting many tissue samples such as blood samples, but there seems to be no standard way of collecting urine, which leads to very different rates of contamination.

I would like to think that, in the future, there would be a standardized way of collecting urine samples, especially when one is checking for infection. I would like to see the widespread adoption of this device.

I appreciate the costs associated with the device, but I think that it is offset by not having to repeat urine samples and by being able to better diagnose and treat a urine infection.

If someone has a urine infection, because the urine sample has not been collected properly and comes back showing contaminants, we may be doing that patient a disservice by not giving them the appropriate treatment, due to faulty urine collection.

I think we have to offset the cost of the device against the better and more accurate diagnosis of patients. Actually, if you repeat less urine samples and reduce the retest rate that results from the first sample not being collected properly, then I think you end up saving money.

I would like to mention how long new innovations take to get adopted widely in the NHS. At a recent conference I attended, one of the speakers, who was a head of innovation, said it takes around 17 years, on average, for an innovation to progress from the inception stage to becoming widely adopted.

One of the challenges for the NHS is to shorten that timescale, so that when you do get something that's innovative, such as this, there's a methodology for widespread adoption.

With regards to current incentives, are the labs paid based on the number of tests that they do, meaning there’s a lack of incentive to want to use the Peezy device?

Yes, that's true, although you would hope that professionalism would mean you just want to get the right diagnosis the first time and not have to repeat samples because there's some financial incentive.

Perhaps there could be a mechanism whereby labs with lower contamination rates are rewarded or recognized in some way. We should be able to think of an incentive that doesn't actually penalize the lab for processing less samples.

At the end of the day, we should be thinking about what is best for the patient: having one decent sample and getting a proper diagnosis or keeping them coming back and repeating urine samples because they've not being collected properly.

Where can readers find more information?

About Prof. Frank Chinegwundoh

Chinegwundoh FrankI am a consultant urological surgeon of 20 years standing, at Barts Health NHS Trust. My experience in the NHS amounts to over 30 years. I have particular expertise in prostate cancer.

I published the first paper in the UK demonstrating that black men have a 2-3 fold risk of developing prostate cancer compared to white men.

I won a national prize in 2012 - the Quality in Care Excellence (QiC) Award saving lives category, for setting up the Newham prostate men’s community clinic.

I demonstrated that men of all ethnicities would attend attend a community setting to access information and testing for prostate cancer. The cancers picked up were all early. In 2014 the project won an award in the Civil Service diversity and equality awards.

I have an interest in the management of recurrent urinary tract infections.

I am co-chair of the Prostate Cancer Advisory Group, which provides advice to Public Health England and the Department of Health on screening, early detection, international initiatives, new treatments and resourcing. My co-chair is the CEO of Prostate Cancer UK.

I am also a trustee of the National Federation of Prostate Cancer Support Groups (aka Tackle prostate cancer). This charity is the voice of prostate cancer sufferers and their families.

I have the accolade of having been awarded a MBE for services to the NHS in 2013.

In December 2014 I was made Honorary Visiting Professor to City, University of London for my research and teaching contributions.

April Cashin-Garbutt

Written by

April Cashin-Garbutt

April graduated with a first-class honours degree in Natural Sciences from Pembroke College, University of Cambridge. During her time as Editor-in-Chief, News-Medical (2012-2017), she kickstarted the content production process and helped to grow the website readership to over 60 million visitors per year. Through interviewing global thought leaders in medicine and life sciences, including Nobel laureates, April developed a passion for neuroscience and now works at the Sainsbury Wellcome Centre for Neural Circuits and Behaviour, located within UCL.


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