University Place  Marshalyn Yeargin Allsopp A Population Perspective on Cerebral Palsy  March 1, 2014 UP990   cc >> Okay, I'd briefly like to describe what I'm going to present to you today. The first is why cerebral palsy is an important public health issue, describe a public health model for CP, and I'm going to refer to cerebral palsy as CP, describe cerebral palsy tracking, an overview of CDC's cerebral palsy tracking system, the latest findings on the number and characteristics of children with cerebral palsy, and why we say that our data provide more than just the numbers. Dr. Ward has done a wonderful job of describing our definition of cerebral palsy, and I'm happy to report that I also have divided the definition into four components. I will not go over this. It's nice when we have consensus. I will not go over this in great detail, but just to remind you it's a group of permanent disorders, it occurs in the developing brain, we've had a lot of information about the types of legions, malformation, other abnormalities that occur in the brain. It affects the development of motor skills and posture, and it's due to non-progressive disturbances. And we also heard a lot about the fact that although the underlying causes of cerebral palsy are static or unchanging, the clinical manifestations occur and change over time. We also heard from Marlena Holden about our definition of developmental disability. So I don't need to go into detail, but in order to talk about why cerebral palsy is important, we need to first focus on why developmental disabilities are important. 

And we know that they're important. We know that about 15% of children have some type of developmental disability, and by that we are talking about a range of disabilities such as cerebral palsy, autism, ADHD, learning disabilities, etc., there are many. But we also know that cerebral palsy is common, that one in 323 children have CP, and that CP is the most common form of motor disability, and that's our focus today. Children with developmental disabilities including CP require increased pediatric health and specialist services, not just for their underlying condition, as we have so eloquently heard, that these children have a range of other conditions that require extensive care and a multidisciplinary approach. Cerebral palsy is costly. Medical costs for Medicaid enrolled children with CP were 10 times higher than for Medicaid enrolled children without CP. And per person lifetime costs associated with CP are estimated to be about one million dollars in 2003 dollars. It's probably more costly today than 10 years ago. Here's a beautiful quote from Sandy, and Sandy is going to be participating in our panel later. She's a parent of a child with CP, and her full story is available on our website. 

But here's what Sandy says: "Every aspect of our lives is shaped by the over 1200 hours a year it takes to take our daughter with CP to her more than 200 appointments with nine doctors and five therapists; deal with insurance; find needed equipment and services; do therapy with her at home; address her behavioral issues; spend extra time on her schoolwork; supervise almost everything she does to maintain her safety and maximize her independence; and make the extra time for her to do the things other kids do so quickly and easily." And I'm sure that many of you in the audience can identify with Sandy. This is a public health model that we use to describe our cerebral palsy activities. The first part of the model is surveillance. Surveillance means counting how many children have the disorder in a particular community, and we call that population base, and we describe the characteristics of those children. The second stage in this process is epidemiologic research. So we take the information we have and the numbers of children who have the condition and compare them to children who do not have the condition, that's known as a case control approach, and we identify risk factors and protective factors as well as potential causes for CP. The third step is prevention. And, of course, we're very focused on prevention. That's the goal. That's the reason that we do surveillance and research is so that we can identify prevention strategies, and if we're not able to completely prevent the condition, at least to lessen the impact of the condition. 

If we are fortunate enough to develop prevention strategies, then we use our surveillance methods again to evaluate our prevention programs. Now, in the middle, and extremely important to all of these steps, we have partnerships. By partnerships we mean the partners that you have in your local community as well as the partners that we have on a national level. We could not do any of these activities without the partners who are there to support us every step of the way. What is public health surveillance? And to us, surveillance is a good thing. It's a positive term, and there's a very specific definition. It is the ongoing systematic collection analysis and interpretation of data essential to the planning, implementation, and evaluation of public health practice closely integrated with a timely dissemination of these data to those responsible for prevention and control. And I want to emphasize the last part of this definition because many times I think there's the impression that we just collect data and provide numbers just for the sake of providing numbers. But that's really not what it's about. What we're trying to do is to use these data to disseminate the data to those responsible for prevention and control. 

That's the bottom line. So how do we do this? How do we track cerebral palsy? How do we know how many children these communities have CP? We do that through our Autism and Developmental Disabilities Monitoring, or ADDM, CP network. So you will all recognize this is a map of the United States, and the colors represent the states that are involved in our ADDM network. For this surveillance year, for 2010 and 2012, we have funded 12 sites. All of the sites are required to ascertain children with autism and to report those findings as part of our network. This is mandated by congress through the Children's Health Act of 2000 which said essentially to us at CDC create a surveillance system across the United States to count how many children have autism and other developmental disabilities. So, fortunately, in that language it said and other developmental disabilities. We have been collecting data. This is since 2002. And we collect information on children that are eight years old in all of the sites that are funded. 

Beginning with 2010, we have collected information on children who are four years old with autism in addition to those that are eight years old in select locations. All of the ADDM sites have the opportunity to also conduct surveillance on conditions in addition to autism, cerebral palsy, intellectual disability, hearing loss, and vision impairment, and we have surveillance for these five disabilities in metropolitan Atlanta. We also have seven sites that in addition to autism have surveillance of intellectual disability, and we have four sites that are doing surveillance for cerebral palsy. And the four sites make up our ADDM CP network, and the sites are Missouri, Wisconsin, Alabama, and Georgia. How do we do this? What are our methods? First of all, we have two stages in our process. We use multiple sources within the community. These are health and education sources. The sources educated, diagnose, treat, and provide services to children with developmental disabilities. All of our information is from records. We do not examine children. 

We have a group of trained abstracters that review and abstract these records at multiple sources in the communities as part of the ADDM network. That's the first phase. The second phase is we have a group of trained clinicians, and the clinicians are people with expertise in developmental pediatrics, neurology, OT/PT that review the abstracted information and code it into a summary form, and then use a systematic approach to evaluate the data that have been collected and determine whether these children meet our case definition. For cerebral palsy and for all of the children in the ADDM network, with the exception for those for autism for the four-year-old surveillance, we're looking at children that are eight years old. And for CP, we're looking at children who either physical descriptions in their record that are consistent with a diagnosis or possible diagnosis of CP or they have a diagnosis from a professional in the community of CP. We also have determined that we're looking at this information in children that are two years old or older because as Dr. Ward pointed out, the physical findings for CP can change early on, and some of these children actually wind up without a diagnosis of CP later. So we've established that we're looking at children from age two, and the surveillance year we're interested in, the children must be eight years of age. So this is our definition, and we have already, this has already been described to you by Dr. Ward. It is the consensus definition that he described. It makes the point that these children have more than a motor disability. 

They have a host of other conditions. The impairment in motor function may result clinically in paresis, which is spasticity, involuntary movement, which is dyskinesia, or incoordination, which is the ataxic form of CP. The next part of the definition is extremely important because it describes what CP is not. And we just had a presentation on that. So it is not conditions that are transient, not conditions that result from progressive disease of the brain, not conditions due to spinal cord abnormalities or injuries. Now, the last point in this definition I'd like to really emphasis because as part of our CP ADDM network we do collect information on children who have post-neonatal events. And these are injuries, infections, and other events that occur after 28 days of age. They are post-neonatal. We think it's extremely important to count those children as part of our CP network because from the standpoint of prevention potential, the opportunities there are great. So we're talking about, again, infections that may occur such as meningitis, encephalitis that maybe would be prevented by immunizations. 

We're talking about injury, shaken baby syndrome, and other types of injuries that occur. Again, from a public health perspective all of this accounts for only about 10% of all the children with CP. We think that it's a great opportunity from a prevention standpoint to intervene. So when we talk about collecting information on the number of children that have CP, we use an epidemiologic term known as prevalence. Prevalence a ratio. It is the number of eight-year-olds with CP in the geographic area that we're interested in during the surveillance year of interest. The denominator is the total number of eight-year-olds in the population, and that comes from census data. And that's prevalence, and I wanted to point that out because I'll go through some numbers here and some prevalence results. This is our last published report from 2008, and it's titled Prevalence of Cerebral Palsy, Co-Occurring Autism Spectrum Disorders, and Motor Functioning - Autism and Developmental Disabilities Monitoring Network, in the US for 2008. Our data are based on eight-year-old children living in these four areas that I identified. 

And here's our prevalence. It's 3.1 per thousand or one in 323 children with CP across the network. This is our website. You can go there and you can view our community report which is a nice summary of the data from our published report, which was in Developmental Medicine and Child Neurology and the citation is at the bottom of the slide. With all of our reports and with reports that other people have published, boys are more affected than girls. And so we see this in each of the sites that is the case. When we look at race specific prevalence, we know that black children in all the sites have a higher prevalence than white children, and, actually, the prevalence estimates in white and Hispanic children are pretty close. And the numbers are really small in this group. I think that it may grow over time, but we generally report the results from Asian Pacific children but we think that the numbers are small so we're not sure that we have a lot of confidence in those numbers. When we look at the subtypes, and we've already heard from Dr. Ward what the subtypes are, and, fortunately, there is agreement. 

He said that about three-quarters of the children have spastic CP, and he must have been looking at our data. [LAUGHTER] Because about 77% of the children from the ADDM network, isn't that great, have spastic CP. And you now know that the non-spastic types are the ones that we talk about when we talk about dyskinetic, ataxic, hypotonic, and dyskinetic ataxic. That's a much smaller percentage. It's 8.2%. And then we have this group of others, and they're mixed CP, spastic ataxic, spastic dyskinetic, and then we have a group of children where all we know is that they have CP and CP not otherwise specified. We can't really categorize them beyond that. I know that Dr. Benedict is going to talk about the gross motor function classification system, so I will just say that this is important background for some of the results that I'm going to present. So, as we heard, there's the GMFCS, and it has five levels from children who walk without limitations through children who have limited or no walking ability. And level three describes children who walk using a handheld mobility device such as crutches, cane, or walker. 

And the reason that's important is because for some of the children, the information that we have in records does not allow us to determine a very discrete GMFCS level. So we have another term known as walking ability that collapses the five levels into three, and we see that levels one and two equals walks independently, level two under walking ability is level three under GMFCS, walks with a handheld mobility device, and levels four and five are collapsed as limited or no walking ability. So the way that we use this in our report for 2008 was we noted that about 58% of children walk independently. That's level one. And level two is obviously a smaller percentage use a handheld mobility device. Then we have almost 31% of children have limited or no walking. So it was a nice way of describing from a functional standpoint what these children look like. We know that there are these other categories such as spasticity, dyskinesia, ataxia, etc, but it doesn't really tell you how the child functions. And so the GMFCS and looking at walking ability allows us to say something more about the functional level of these children within the community. We've already heard about the co-occurrence of many other conditions with CP, and we were able to look at two really important developmental disabilities that occur with children with CP. 

And using our ADDM methods, we have looked at co-occurring epilepsy and co-occurring autism. We found that 41% of the children in 2008 with CP had co-occurring epilepsy, and about 7% had co-occurring autism, which we found really interesting since the population prevalence of autism is about 1%. This is a much higher percentage of children that have autism and there hasn't been a focus on this. We were able to identify two other population based studies that looked at this. And those studies, when they used a record review approach as we did, had a report that was very similar to our results. And when they clinically examined the children and looked for signs of autism, actually one study found that about 15% of the children had autism in addition to CP. And the importance of that is recognizing that these children have more than one disability, screening, and diagnosing these conditions and coming up with an appropriate treatment plan that deals with all of the conditions that affect the child not just one. This is the page from the Wisconsin community report. And I believe we have some copies here, Carrie. Outside? And so please pick up one and look at the specific information as it relates to Wisconsin. 

In the community report, as I said, there's a page for each of the sites and gives very specific information that we hope can be useful for provision of services, planning for services within the particular communities. Okay, so our data provide more than just a number. What else do our data help us with? Increased awareness of CP, our data provide a more complete picture of children with CP, can guide research of other scientists, and can help communities to coordinate service delivery. So I'm going to give just a couple of examples of how we have tried to delve into some of the numbers that we produce and understand more about CP. So this one deals with the fact that we have always noted since we started looking at the data and making reports that there's this disparity in terms of the prevalence of CP in black children compared to white children. So we see that the overall prevalence was 3.7 per thousand in black children and 3.2 per thousand in white children. So this is where we used our walking ability levels, one, two, three, and we were able to look at this ratio between black and white children, and what we discovered is that this level where we're talking about limited or no walking ability that black children had a statistically significant difference related to white children. Now, we don't know why, but it raises a lot of questions, and it points in the direction of further research so that we can try to understand this. And reading some of your minds, you probably want to know what about some of the maternal and birth characteristics. What about low birth weight and other factors? We did look at that and it didn't make a difference. 

So this is not explained by the larger number of children who have low birth weight in terms of black children. So we still don't understand this but, again, leads the way for further research. Also, I pointed out that CP is costly, that we have this Medicaid database that we have used to look at medical costs, and the medical costs are here. So what we found was that for children with CP alone, the medical costs were 10 times higher than for children without CP or intellectual disability. So this is the box here, the $1,674, compared to CP alone, the $16,721. We also found that for children with both CP and intellectual disability that medical costs were 26 times higher than for children without either. So that's the comparison here. Neither CP or intellectual disability was $1,674, and for children with both it was $43,338. And medical costs for children with both CP and intellectual disability were almost three times higher than for children with CP alone, and that's the difference here. We see that. 

So, again, just recognizing what CP looks like and also the impact of CP in many different areas. So here's another slide that I wanted to present because it shows that because we collected data that we have the ability to answer some really important public health questions. So in the early '90s, there was an observational study from California that showed that women who received magnesium sulfate, which is given clinically for arresting preterm labor and is also given for preeclampsia, that those women that received magnesium sulfate who had babies that were born low birth weight, those babies seemed to have a lower prevalence of CP. And the question was, was this due to the magnesium sulfate that the mothers received? So the first question was, does magnesium sulfate affect the mortality of these infants? So, in other words, if the babies die, then we can't count them as having CP. So we were asked to use the data that we had collected in Georgia on very low birth rate children and look at the CP outcomes and go back and look at the medical records and see how many of the moms had received magnesium sulfate and then compare that to the CP outcomes. And we also decided to look at intellectual disability as well. So we were able to actually confirm the findings from California in that we found that in the mothers that received magnesium sulfate that there was what we call this protective effect. That the odds of having a child with CP were very, very low, less than 1.1, and the same for mental retardation or intellectual disability, again the odds were very, very low. So this was an observational study, and you can't really sort of conclude from that that we need to then have a recommendation that all women receive magnesium sulfate if they're in preterm labor. As many of you know, the gold standard for looking at an intervention is the double blind placebo control randomized clinical trial. 

And that's exactly what was done. There have been several of those so far, and here's a summary of one where there were over 2,000 women who were at risk of preterm birth. And they were identified at 24 to 31 weeks gestation, and the cases were randomized. Some of the women received magnesium sulfate and some of them received placebo. And the results again support that this seems to be an effective intervention. That the prevalence of CP was lower in the magnesium sulfate treated group, 1.9% versus 3.5%. And the risk of death did not differ in terms of the treated group compared to the untreated group. So where are we with this? We are still in discussion. A group of clinicians, a group of epidemiologists, public health folks, we are still trying to agree upon moving forward with a public health recommendation. But it would be very exciting if we could get to that point because we think that the ability to prevent a substantial number of CP cases would occur if we could get to the point that we could make this recommendation. 

I will say that it is used a lot in clinical practice even without the recommendation. So I'd like to acknowledge here that it takes a village. That we have a lot of people standing behind me and behind us at CDC as part of our ADDM network who work with us on an ongoing basis. Our methods are standard across the network. We have primary investigators, project coordinators, abstracters, data managers, programmers, clinician reviewers, epidemiologists, and a lot of other program staff. They're all dedicated, hardworking, and resourceful, and we thank each one of them. We're so happy to have an opportunity to come and visit some of our communities and actually see what we do in action and meet some of the people from the data sources and some of the staff that we ordinarily would not be able to interact with. So it's wonderful to be here. And I'd like to thank my colleagues at CDC who've assisted with this presentation. So, looking to the future. 

CDC brings a unique public health perspective to studying health issues in large populations. Our tracking data on overall prevalence, subtype, co-occurring, developmental disabilities, and motor function can do a number of things. First of all, improve our understanding of CP and help communities plan for services and develop policies that promote full participation. So in terms of improving our understanding of CP, I just want to say that we are now collecting neuroimaging results, and we saw some lovely examples from Dr. Ward about the possible correlation between what you see on an image and what you see clinically in these children. This is a pilot study this year, and we are exploring whether it's feasible to do this across the network. And so we will be looking at this in order to understand if there are lesions in the brain. We don't know if you can see this on all of the scans or not. If so, what does the pattern look like? Maybe what's the timing of the event? And we hope that with that there would be some opportunity to also think about whether there's a prevention related to understanding more about what's going on in the brain. There's still a lack of population based data on CP. Look at risk factors and causes for CP. 

That's a tremendous area of potential growth in terms of doing more. There are huge transition issues from childhood to adulthood and issues related to the overall quality of life. So with that, I'd like to thank you for your attention, and I don't know if we are able to have people ask any questions. Okay, just a few. Thank you. [APPLAUSE]