Computer generated transcript

Warning!
The following transcript was generated automatically from the content and has not been checked or corrected manually.

Um students who have joined probably listening or I don't know whether they're trying to talk. So um good afternoon everybody. Um My name is Anita Chakrabarti. I'm a public health consultant. And um today's lecture is going to be a snapshot and it is a snapshot in the slides, you'll see some um links into additional resources um If you need to get hold of them. Um Today's um uh teaching is a snapshot of um screening programs and population screening programs and this is in particular relevance to the United Kingdom's. So, in your individual countries, you may have different screening programs. The underlying principles of screening programs is pretty much um same, same or similar. It's just that you may not have the whole um cohort of um screening programs that you need in your country's. Um or you may have other different screening programs in your countries which are not prevalent in the United Kingdom. So this is a snapshot of screening programs um and, and, and the, and the public health principles behind them. Um and also um uh just a sort of a brief introduction into some of the screening programs and how they work. So what is population screening? So population screening is a process of identifying apparently healthy people um and um who may be at an increased risk of disease or a condition. And they can then be offered information, further tests, appropriate treatment to reduce their risk and or complications arising from the disease or condition. Now, you may be aware of some of the screening programs that are in place already. So in pregnancy, we do a screening program very early in pregnancy to understand how, how the pregnancy is. So we do a scan but we do the screen programs, which is um which is a combination of scans and blood tests to look for some markers to see if babies have got congenital abnormalities. Um Once that's offered to women, women or two couples, there is an opportunity to then advise them to give them more information and then support them in their choice as to how to then take forward that pregnancy. Um you know, some people might want further tests, some people might want, don't want to continue the pregnancy and some people might want to continue the pregnancy. So there is a whole lot of um support and uh and and advice available. So to start a screening program is just not about starting a test. It's also about making sure that we've got all the support mechanisms forward. And so this is the definition of the screening program. So in the United Kingdom we've got a National screening committee, United Kingdom National Screening Committee and you can see the um the web link there and, and if you go onto the web link, you'll be able to find more information about screening programs in general and also screening programs within the United Kingdom. So what does population um screening, um what does that, what does it mean? And what, what, what does it do? So basically what we're doing is we're looking at healthy people, okay. So everybody, all of us, you know, um are born healthy so we do not have any, any clinical conditions happening. Um and, and we are otherwise fit and well, and we're just moving forward screening is the process of identifying healthy people who may have an increased chance of a disease or a condition. It can be helpful to think of a screening like a seve. So as you can see this is a bit of a seve. So basically because of certain genetic markers markers, because of cultural variation, because of our lifestyle, because of certain age characteristics, we become at risk of certain diseases. So for example, we've got a breast cancer screening program. Now, breast cancer is preventable um as in uh you know, um and it can, you know, deaths from breast breast cancer are preventable if diagnosed early. So we know that we've got a screening program if you do that. Um We, if you put that, if you screen women particularly in the age groups, 50 and above the chances of us speaking, breast cancer, early treating them and giving them a good quality of life. The treatment is there and that can be offered. So therefore we screen healthy women. Um uh and then we look for women who then have um any low grade breast cancer and then once they have been diagnosed with that or any other pathology, we can treat them. So for example, hair, as you can see, there is people who are healthy, they're going through a screening test which is like a seve and then we are identifying more people. So for example, in our breast cancer, um uh so if the, if the mammogram or they suggest that there is um suggestions of something happening in the breast or there's changes, then we do further tests, we have I advise and support treatment or no further actions. So for example, if they, if we diagnosis benign condition, then advise and support is given and no treatment is required. If there is um we do further tests and there is no further action required. That's what that's offered. And if, for example, uh early stage breast cancer is diagnosed, then we can offer further treatment. So the C represents the screening test and most people pass through it, many, many, many people pass through it. This means that they have a very limited chance of developing the condition. Um They've been screened for and, and we don't stop there. Um So um we, we screen them every five years. So there is there, you know, as, as your, for example, for breast cancer, as you grow older, there might be a small increased risk of you developing it in future life. So we then repeat it for you in a couple of years time and, and then make sure that you're not developing an early stage breast cancer. So the, as I'm saying, the people left in the seeds. So these two people that have got a high chance of having the condition, so then the screening team picks them up and then those are the, those are the support mechanisms that takes place once the population screen, once the screening program identifies, used to be somebody who's got high risk, the significant ethical considerations of having critical screening programs because what we are doing eventually is we are taking healthy people and we are subjecting them um to um some tests to diagnose um something that they may or may not have. So, a whole lot of choice is available. Um So it has to be an informed choice because you might be somebody saying, you know what, I'll take my chances and I don't want to have the breast cancer screening because I'll just take it as it comes. Um um and, and that's your choice. And you can say, well, I'm opting out of the screening program because I don't want this to happen. Um So there's a lot of advice and support that happens before women um or people get into screening program so that they can make an informed choice. And that is why this, the ethical considerations are important because if I was going about my life, I'm fit and healthy otherwise, and nothing is a problem. And then suddenly, um you put me through a screening program and that diagnosis, something that will have implications on my entire lifestyle. So my, my consideration has to be based on the information that I get before I go into the going to the program. And there is lots of support throughout the screening process to make sure people have got that informed choice. So getting into any screening program, you need that informed choice, the screening can save lives and improve quality of lives. For example, if you diagnose cervical cancer early, if you're diagnosed breast cancer early, the deaths can be preventable from those cancers. Um And, and so it's quite important that that has to be explained to people who are going into those screening programs in certain screening programs. It reduces the risk of developing serious conditions or complications. Um But, but there is always a but a screening test is as good as we've done the evidence in the research behind it. There could be false positives, all false negatives in all screening programs. And that's why it's important for us to just make sure that we have given all of the available information up front for the person going through the screening program to make a choice, the information and how you give it is also quite sensitive and it's quite important because people don't always understand what you're telling them. People don't understand the complexity of the, of the programs. People also don't understand it. It's if it's given in, in, in, in a language that's not their language. So in, in the UK, we give most of our information in English. So for example, in my practice, a couple were given information about screening uh antenatal screening for Down syndrome. Um only they didn't understand anything. So um when the screening program happened and there was some abnormalities detected in this unborn child, the couple were furious because they thought they had been subjected to some tests that they were not aware of or they've given, they're not given consent to and going back the issue was that they were given that support and they were given that information, but it was in English. Um But more importantly, although the clinicians offering the advice were very particular and absolutely assumed that they understood clearly, the couple hadn't quite understood. So it's very important that there is informed choice based on the all available evidence based research. And so how are decisions made about screening programs? Um So the, so as in the, you know, United Kingdom, we've got a United Kingdom National screening committee which leads the assessment of the condition. So if we say um there is a condition that we want to actually, we know that the disease pathology is such that if this condition is diagnosed in a very early stage, then we could make a difference to the impact and lives of people. Um So it has to be a condition that has got a good fit your uh like a pathophysiology that we understand and that it's got a latent phase whereby if diagnosed early, we can make a difference. Also, the screening test has to be quite simple. So for example, if the screening test involves the person going into an MRI every two months, that's not going to happen because we don't have that many MRI machines, it's not cost effective and it might not be um suitable for people. So the screening test has to be a simple one that can pick up something quite um quite a sort of reliably um quite early on in the pathology. So, for example, chlamydia um screening programs, um chlamydia, you know, you just pin apart the pot gets analyzed the, you know, you get diagnosed with chlamydia or you don't get diagnosed with the media and knowing how rampant chlamydia is and knowing how the media causes devastation. Um as when it's when, when you get a chlamydia infection, particularly for, for the women anatomy. Um uh it's a simple test, but it picks up most of the time. And so it's, it's a good screening test to use, particularly in that young age group where chlamydia is so rampant. And then there has to be a treatment for the condition. Um So once you get diagnosed with the condition, there needs to be a bit of a treatment. So you diagnose people with chlamydia, you know that you can give them antibiotics and you know that they'd get better. Um And, and that is great because if, if chlamydia cannot sometimes be a symptomatic and can continue to have um uh and leave people with really longstanding um morbidity so we can avoid that. So there is a treatment. So we're then doing a screening so we can identify people early and we can provide the pro uh we can provide treatment for it and then it has to be run as a program because we can't say, well, we're doing this screening in this little geography here or we're only offering it to 16 year olds in this school and not to any other school because that way, then you are widening the inequality. You're basically kind of saying, right, you know, um you know, people in this particular geography or in this particular school or in this particular area will benefit from it the rest of the people want. So, so screening programs have to be running as a program and again, so you could go to the website and see the program appraisal criteria. So you can't decide wake up one day and say, oh, this test is very good at detecting a particular condition early. Let's just use it on masks population and start it as a screening program. You can't do that this very specific criteria by which tests get appraised and the evidence basis looked at before they, they're made viable and they're effective and appropriate for a screening program. So that's what I was explaining. So the some of the conditions that we need to be absolutely assured of before the test becomes a screening program and that is there is a natural history of the career. Um And, and there is an, it's an important health problems. So chlamydia is an important health problem, particularly in young people. But there's a natural history, we know chlamydia and it causes the infection, how it damages the, the internal um body of uh young people. So there is, there is absolutely um uh important history behind that, that we are aware of. There's an epidemiology and a natural history answer to that exactly what I've said and it's cost effective. So the comedian screening program is being apart pretty cheap. We then analyze the urine and we know whether they've got committee or not. Um If the career status is, is not understood, then we don't, then we can't do a screening program. If any aspect of that natural history of the disease is not understood, then we can't use uh when we can't use any tests to under undertake screening for that program. As I was saying, the screening test has to be simple, it has to be safe, it has to be precise, it has to be a validated test. So we should have run the test in the lots of people, lots of normal, healthy people to then detect the people, um um that we want to identify. So it would have a validated test. So it's quite important. So again, just because the test is picking up something doesn't mean that we, we, we take it and we, we kind of say, well, that's a, that's a validated test and we're going to use that. Um And we also need to know where the the test values are known. So what is the, what is the limit of it? So at what, at what stage does it become positive? And at what stage is it negative? Is there a wide variation of sort of, you know, of data points where it, you know, where it could be um sort of positive or negative or being that great category? So it's very important that the test is quite specific. So chlamydia positive means x number of um you know, ex ex sort of metrics in the in the urine that will detect community chlamydia chlamydia negative would be if nothing is detected in the urine. So these cut off points are absolutely important and agreed it has to be acceptable in the population. So for example, like we have screening programs which in certain communities and cultures is not very um suitably accepted. So we have to do a lot of training and teaching in those areas to make sure that they understand the importance. So for example, cervical cancer screening program means you need to go in every five years um into a doctor's surgery or in a nurses practice and actually bear yourself and have a cervical smear taken. Now. Um, it is acceptable in most women. But so some women culturally that is not acceptable in some people, it's not absolutely, um uh, you know, palatable, they just don't want to do it. People would say who've been, who've been exposed to sexual violence and other things, um, are absolutely traumatized for something like that. So we have to pick a test that is generally acceptable to majority of the population and then make amends for people who may not be um, uh suitable or may, may not want it. And therefore they would need some additional support and guidance. And then there should be a policy to investigate if the test is positive. So if your chlamydia positive, you know where to go, you need to go to your doctor or your nurse and get, get, uh, get, get your treatment for it. Um If, if the screening, uh, if screening for a subset of mutations criteria for selecting subset, should be clear. So for example, like we're doing the breast cancer screening program which identifies people are, are uh you know, who may have breast cancer very early on. However, there are certain families and certain women who are at increased risk of breast cancer anyway, because they might be carrying one of the two um highly mutant genes called BRCA one or BRACA to now, do we screen for them? We don't screen for them. But if, if a family is um got a high um sort of um uh you know, high numbers of people in the family with breast cancer, then we will test them for the BRCA one and BRCA two genes. Um and to, to look at some of the subset of the mutations to see if we could pick up if they're positive for those because if they are positive for those genes, then there's chances that they would be probably um at, at a higher risk of developing breast cancer. So then there's advice and support for them for those families. So I talked about the intervention, the intervention has to be effective with the evidence of the intervention in the presymptomatic stage leading to better outcomes. So the comedian screening program, you know, you pick them up in healthy people who don't have symptoms. So the effective intervention is giving them antibiotics as a prophylactic to treat them. Um It has to be an evidence based policy as to who should have the intervention in which intervention should be offered. So for example, like, you know, um if say that the test shows um in in breast cancer screening and uh an ambiguous finding, then the dis discussion would be having with the person who have had that result to make sure that there is an evidence based um support and advice and treatment available um for the condition that they, they've been diagnosed with from the screening program. So there has to be a huge amount of evidence behind based behind the policy, the evidence for programs is generated through high quality randomized control trials that the program reduces morbidity and mortality. So basically, you would have subjected the test to, you know, groups of healthy people and then um uh groups of healthy people would have a placebo, you'd have to combine um evidence between those who have had the test, who have not had the test. Um and then um the fetal anomaly screening. Um So for example, in the fetal anomaly screening, high quality evidence that the test accurately measures the risk is established and then only it's used as a program and there is, there is alongside, there is also acceptability um evidence that's collected. So that, that, that the the test that we're putting in is actually acceptable to public and professionals. And this is very, very important. The benefits for the program should outweigh the physical and physiological harm and it has to be value for money. So for example, we've got the aortic artery um the aortic aneurysm screening program, the triple A program in the United Kingdom, which is something that very um people who are, you know, quite elderly are subjected to. Um but then the interventions could mean a whole lot of invasive procedures, procedures. And, and so that has to be explained to the people that um that the the benefits of having the program and knowing something this early, um actually outweighs the physical and psychological harm. So, diagnosing Comedia early means you are at uh you, you will be protected from having any um sort of problems um in future. And, and, and so, you know, it's just a simple medication and so the benefits of having the screening program strongly outweighs any harm of having the program. I mean, it's simple, you just been apart and somebody will pick that up, right? I think I'm going to check on chat because I'm seeing. Okay. So there are some questions here. Okay. Okay. So there's somebody so Assad is from Kiev. Welcome Assad. But you're, you're in Mumbai just this very minute. Yeah. So you're saying here that some blood tests to screen multiple tumor markers? Well, that is why I was just trying to explain to you that you cannot stand suddenly random, randomly start a screening program. There's lots of private companies which kind of cash in on this and kind of give people sort of um um hope and assurance that doing multiple risk, multiple tests will pick this up. This is not one that I have. I'm familiar with. Let me just Google it and see if I can find anything. Yeah, not one that I'm familiar with. Not one that is part of our, our screening programs here. Um Assad. So I won't be able to say that. Um I know for sure that, that it's, it's the, the evidence base is established. So sorry. Now I've lost everybody. Give me two minutes. Oh, I knew share. No, I haven't done new shares. So, oh, I'm here. Okay. Let's see. Stop share. Um Just go ahead. You could share. Okay. Can people still see the slides? Can somebody say yes or no, please? Yes. Okay. Okay, no problem. So just on that question as in is uh subjecting people to these kind of tests. Now, if it is not a nationally um um uh sort of nationally mandated program on the NHS, I know you're kind of saying this is available on the N H S. Um What we need to look at is, is it an NHS um screening program on the screening? Um So this is a trial. So these are, this is trial. So this is trialling to see if this particular test can be introduced. So it's not an established um screening program as yet. There is a trial going on to make sure that um there is uh sort of every being developed to make sure that the, if it was going to be ruled out as a screening program, so it takes years and years and years. So this is a trial that's happening on the NHS. Did, did that answer that question? Whoever is asking the question? Is it Dr Addy? Dr Addy? Are you here? Can you on mute and, and ask you a question? Okay. I guess he's, he's not being able to talk, um, is non radiating MRI the safest imaging modality. Now again, it's important for us to understand what the safety profile of, uh, of different investigations are. Now, it could be safe for somebody and not safe for somebody else. So that is what exactly what the screening programme does. It evaluates every aspect of the program, including the treatments to make sure that the training that the screening modality is a safe version of, uh, of what is being offered. And the same information is then given to patient's before they pick up on the, before they pick up, um, there before they subject themselves to the screening program so that they know fully informed how they're getting into it. Okay, I'll go to carry on. Okay. Good value for money. So as I said, if you, if you introduce a test, that means somebody's got to have an MRI every, every so many years. Is that cost effective or not, it's important for us to understand that evidence as well before we introduce a screening program. So have we been talking about this as we're going along, this clinical management should be optimized. We've talked about that all other options of managing the condition should have been considered. So for example, chlamydia screening, we know the best form of treatment is giving them the antibiotics, breast screening program. The best way of doing it is act going in and taking out the area that is generating abnormal breast cells, cervical cancer screening. We know, so the clinical management should be optimized before starting the screen program. So we know exactly know what the treatment is. And before we start the program, we know that's where it is and we know how to support people if they become screen positive. Now, quality assurance standards are absolutely important and fundamental. So for example, you're running a screening program, you need to know for sure that there is quality assurance metrics at every possible step so that you are picking up people who have um who maybe were false positive. Uh You're picking up how many false negatives. So ideally, you should have very low false positives or false negatives. Ideally, people you've called for and haven't taken up the vaccine uh vaccine uh screening program, you should have very low numbers of that. So an ongoing quality assurance program has to be managed and maintained as part of the program and adequate staffing facilities and and a lot of training for people who are delivering on the program. And there has to be evidence based patient information and, and, and, and, and also anticipate public demand for widening eligibility criteria because you see the learned people might say, hang on a minute, you know, um I I want to breast cancer screening from when I'm 30 odd years old because I could still develop breast cancer that I know the prevalence is low and uh the incidence is low but still want a mammogram. Now, we then have to use the screening program, the evidence based to say at what age is that is that test more positive, more sensitive and more specific and more importantly, is it cost effective to give it to 50 year olds as opposed to 30 year olds. And so we therefore have to develop that justification which we then can go and talk to the public about. Okay. Well, this was a question but look at this conditions, we don't screen for okay. So for lung cancer because there is no specific test that gives us that there is some targeted lung health checks program now, but they're in very, very pilot phase is okay because we're looking at the condition, we're looking at the test, we're looking at the intervention, we're looking at the program and we're looking at the implementation prostate cancer. We don't have anything for screening because the natural history is not very clear, we don't know who to screen So, although you will see lots of, um we, we kind of do the PS psa test prosthetic um um uh screening assays um on particular particular men, but we can't use it as a screening program because the natural history is not that clear and the test is not very specific. So it probably throws lots more test positives than test negatives. And then, and then you're, you're kind of sitting there intervening on, on lots of people, um, without actually having the basis and the evidence to say who, who, who to test it for. So the question still remains. Do we screen or where men or do we screen targeted men? Something like Huntington. Huntington disease. It's an uncommon disease. It's a familiar disease, it cannot be cured. So it's unlikely to be acceptable to the population, to the healthy population to go away and do muscle biopsies and, and, and then make sure that the and, and rule out Huntington disease. So these are some of the examples of uh diseases that there is a lot of clamor to say. Can we have a screening program for? And there is ongoing evidence and review and research to make sure that we've got the right evidence to go back to the public to assure them why we cannot screen for them or even if you're screening for them, it's, it's in very, very targeted groups. So now this is, this is the key bit. So screening test validation happens through these four things. And this you'd probably have learned in your epidemiologic um um lectures, but I'll just go through them briefly here. Um Sensitivity does not depend on the prevalence. Okay, sensitivities. How sensitive is a test? How good is it in picking up a condition? Specificity also does not depend on the prevalence and specificity is. How many false negatives do you have? Ok. Positive predictive value is dependent on prevalence. So how reliable is your test in picking up somebody who is positive? Negative predictive value is also depends on the prevalence. So if you say I'm chlamydia negative, what is the evidence to say you're definitely chlamydia negative and there is no risk of you becoming chlamydia positive. Um and and kind of not being treated for it. So, so these four things are very, very important in the screening program. If you know nothing after screening program, learn these things because these are very important and in your exams, this is something asked. So um so let's look at this. So this is a screening test performance. Um and um so positive um people are a okay disease positive are a disease negative um are no um uh sorry disease, disease negative R C. Um And then screen positive, screen negative tests. People who still turned out to be positive for the disease are be people who um uh were negative um and didn't have a disease were deemed okay. So what we use is this kind of um uh sort of we pre plot them on this on this particular formula. And then we go on to discuss how sensitive is this particular test. Okay. So how sensitive is this particular test is people who have screened positive on the disease on the screening program and have also got the disease. So people who've had the breast cancer, um uh mammogram and screened positive for breast cancer then went and had a fine needle aspiration and then they tested for positive breast cancer. So they are a okay. And then people who tested positive for the breast cancer screening mammogram. But then when they had the F N S C and the fine needle aspiration biopsy did not show that they have breast cancer. So they are see. So we've now got a total of people who are screen positive. So how sensitive is this test? The 10 sensitivity of the test is calculated by the number of positives by the total number of people, number of number of positive, diagnosed people of breast cancer by the total number of screen positives. Okay. So true positives by all those people who are, who have kind of tested, um who've also got the disease and were tested as part of the screening program gives you the sensitivity. Okay. So the proportion of people with the disease correctly identified by the test is the sensitivity. Okay. And this is one of the main main characteristics of a screening program. Specificity specificity for a screen population is the proportion of people without the disease have been correctly identified by the test. So for so these are the people who have actually benefited from actually going through the screening program. So the proportion of people. So I wasn't aware that I had chlamydia. I went in for the chlamydia screening program because they came into school and said, can you be in apart? And now I've been identified with chlamydia. So great. I now know I have chlamydia, I can treat myself for it. So the proportion of people without the disease who have been correctly identified by the test. Okay. So uh so the test didn't detect them but they're true negatives and they're all without the disease. So the thing is they, the test has said they've not got any disease and they've not been identified with the disease. So they are also true negatives. Okay. So the specificity is the proportion of people without the disease and they've correctly been identified. So the people who've been identified with the chlamydia screening test to have be positive is fine. But the people who have been told negative, how true is it that they are definitely negative is identified by the specificity of the test? Okay, please shout if this is not clear. All right, but this is something that I can't explain to you in an hour's talk, you need to go away. And look at it and study it in your own time. Sorry, bear with me. Uh yeah, one. So the positive predictive value, the probability of having the disease after a positive test. So the positive predictive value is the true nature of the test. So when you have the test and the test says to you, you're definitely positive. So you go for your breast cancer screening program, they says we've seen a shadow which possibly means you've got something in your breast. What are the chances of you having breast cancer? Probably pretty high? So the positive predictive value is that factor and it tells you that you've had a test which is positive, the chances of having the disease is high and the negative predictive value is again a very important factor. So if if say I go for my mammogram and it says to me, you know, your mammogram is normal. Now, how positive, how, how confident do I feel in the test that it hasn't missed out any microscopic um elisions or any risk of me actually having the disease? So when there is something quite specific, when the specificity is high, when the negative predictive value is high, then it's telling me that screen test is very, very good in telling me that if it's a negative test and I don't have the disease, okay. So negative predictive value of a test is very important in saying that they're not having the disease after a negative test is high okay as the prevalence increases. So, in a population in 16 year old's, um the the the the prevalence of chlamydia is high anyway. So then the sensitivity and specificity are unchanged, but the positive predictive value increases because you will pick up more people if you do a screen test in under 18 year olds for chlamydia, because you will pick up the, the test is very powerful in picking up both people who are symptomatic and un symptomatic who have got chlamydia and a negative predictive value test, uh kind of decreases. So if they say you're not, I mean, your test shows that you're negative, the chances are yes, of course, it is. But you know, because there is so much chlamydia in, in the, in the in the population, sometimes that negative predictive value may decrease as well. So just to understand that there are some nuances once we're using some of these indicators to make sure that we've got a screen positive ana screen negative test, how um how uh kind of how confident it is in diagnosing something. So these are the population screening programs. And um so as you can see the adult and the young person screening programs, the abdominal ionic screening program, there's a diabetic eye screening programs. So these are in the adult and the young people. Um then there's a cancer bowel screening program. So we've got bowel cancer screening, we've got breast screening we've got cervical screening and then you got the Antenatal newborn screening program, which is a sickle cell thalassemia. So, in certain communities, there's increased risk, sickle cell and thalassemia. So we could screen them for those conditions, particularly in the, uh, to make sure that if they are going for pregnancies, then their unborn child has, you know, they've got the right um, information in, in, in sort of making sure, um, they, they, they're going into pregnancies with that wide open information as to what to do if the unborn child or the child was to develop was to also have sickle cell and thalassemia. We've got infectious disease screening. So, you know, um we, we, we screen for lots of other infections, disease conditions, foetal anomaly screening. We talked about that we screen for Down Syndrome and other other um genetic abnormalities. We've got newborn hearing screening. So this is done in newborns to make sure that um any hearing problems are identified very early so that there is um no impact on the child in their development. We've got a newborn infant, physical examination which is done um as a child is born and is being um in, in the 6 to 8 weeks time just to make sure that they don't have any of the congenital abnormalities. And then we've got the newborn plot spot screening programs as well, um which again happens in the newborn. So these are in many ways, some of the um main um screening programs that we've got in the population in the United Kingdom. And that again, there is a link here and you can see um uh population screening timelines and when they are developed delivered and, and that's kind of a bit of a chronology as to when they happen and when they're repeated and they carry on. So you can look at that and then I leave you with these videos which you can uh use and see for yourself, particularly those um complicated areas as to which screening program do I use? What, what screening programs, what, what investigations can become a screening program? How do I know how valid a screening program is? So you can look at these youtube videos. Um and then you can um identify uh and learn in your own time, some more things about the screening programs. Okay? I will stop share ing and I'll see if there's any questions, any questions, Doctor um Azad. Were you trying to ask a question? Were you trying to raise a hand? Uh No, ma'am. It was just comes up. OK. Thumbs up. Okay. That's, that's all right. Was that ok? Was that easy to? Well, it's a Yeah, so just because I'm just touching on some important concepts around the screening program and just giving you a bit of a high level summary. So, um it could leave with more questions. So my suggestion would be to go and do some background reading, yourselves, particularly around the positive predictive value, negative predictive value, um sensitivity and specificity, which is based on epidemiology, but based basically is kind of gives you how confident you are about a screening program and those, those are kind of quite key. So have a look at them as well and, and make sure that um you know, a little bit more because it might be asked. Okay. Any questions, any, any um uh ambiguity. Nope. Okay. So if you don't have any questions, um then that's absolutely fine. I'll put my contact details onto the um sorry that went before I could even say put my um if you wanted to ask me any questions or sign, get you to uh sign post you two different um different things, then um just, just write an email to me and that will be fine. Okay? All right then. So if that's okay, I will um stop here. Um Is that All right, moderator? Yes, that's great. Thank you very much for your lecture. Okay, perfect. So if there's any questions you come back to me, there's no questions now, then we can end this lecture and thank you very much for attending. Um And as I said, if you've got the recording, then you've got the um links to the uh resources that I've signed posted you to. Please do have a look at them. Okay. All right, then. Take care. Thank you. Bye bye. Thank you. Very much.