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Services for adults with an autism spectrum disorder

7 May

Paul Shattuck is one of those people I greatly admire. He and his group ask important questions in areas which are generally given low levels of attention. Regular readers to Left Brain/Right Brain will (I hope) recognize that improving the research base for knowledge about autistic adults is a high priority of mine. I can’t say as I was exactly pleased to see the abstract below, as it points out the lack of knowledge that we have. But I was pleased to see this topic highlighted. The study (which I have not seen in full yet) is Services for adults with an autism spectrum disorder.

The need for useful evidence about services is increasing as larger numbers of children identified with an autism spectrum disorder (ASD) age toward adulthood. The objective of this review was to characterize the topical and methodological aspects of research on services for supporting success in work, education, and social participation among adults with an ASD and to propose recommendations for moving this area of research forward. We reviewed the literature published in English from 2000 to 2010 and found that the evidence base about services for adults with an ASD is underdeveloped and can be considered a field of inquiry that is relatively unformed. Extant research does not reflect the demographic or impairment heterogeneity of the population, the range of services that adults with autism require to function with purposeful lives in the community, and the need for coordination across service systems and sectors. Future studies must examine issues related to cost and efficiency, given the broader sociopolitical and economic context of service provision. Further, future research needs to consider how demographic and impairment heterogeneity have implications for building an evidence base that will have greater external validity.

It is amazing that after a decade of intense focus on autism research, we know so little. I greatly appreciate Prof. Shattuck’s team taking the time to review the literature. It’s time to put some major effort into filling in these knowledge gaps.

Parental socioeconomic status and risk of offspring autism spectrum disorders in a Swedish population-based study.

2 May

In many autism prevalence studies, higher socio-economic status (SES) for the parents is correlated with higher autism rates in the children of those families. While a conclusive reason for this has not been shown, it has been conjectured that the SES variability could be due to social influences such as access to care.

A recent study from Sweden shows the opposite. In this study, lower income families and children of parents with manual occupations show higher autism prevalence:

OBJECTIVE:
Epidemiological studies in the United States consistently find autism spectrum disorders (ASD) to be overrepresented in high socioeconomic status (SES) families. These findings starkly contrast with SES gradients of many health conditions, and may result from SES inequalities in access to services. We hypothesized that prenatal measures of low, not high, parental SES would be associated with an increased risk of offspring ASD, once biases in case ascertainment are minimized.

METHOD:
We tested this hypothesis in a population-based study in Sweden, a country that has free universal healthcare, routine screening for developmental problems, and thorough protocols for diagnoses of ASD. In a case-control study nested in a total population cohort of children aged 0 to 17 years living in Stockholm County between 2001 and 2007 (N = 589,114), we matched ASD cases (n = 4,709) by age and sex to 10 randomly selected controls. We retrieved parental SES measures collected at time of birth by record linkage.

RESULTS:
Children of families with lower income, and of parents with manual occupations (OR = 1.4, 95% CI = 1.3-1.6) were at higher risk of ASD. No important relationships with parental education were observed. These associations were present after accounting for parental ages, migration status, parity, psychiatric service use, maternal smoking during pregnancy, and birth characteristics; and regardless of comorbid intellectual disability.

CONCLUSIONS:
Lower, not higher, socioeconomic status was associated with an increased risk of ASD. Studies finding the opposite may be underestimating the burden of ASD in lower SES groups.

I haven’t been able to view the full study yet, so I am not sure what influences the authors may be implicated. What they do suggest is that the autism prevalence in lower SES groups may be underestimated in many prevalence estimates. I don’t think this will come as a surprise to many who consider the lower prevalence in the lower SES groups to be an indication of social factors at play.

Mayo Clinic to study adult prevalence and outcomes

18 Apr

A five year project was started this year to investigate the epidemiology and current status of adults in the U.S.. At present we have almost no data on adult outcomes. We have little data using on adult prevalence. Studies from the U.K. have reported a prevalence about 1.1% for autistic adults “…with learning disabilities living in private households and communal care establishments in Leicestershire, Lambeth and Sheffield”. This is slightly higher than reported in 2007. The studies were survey based. The survey was calibrated with testing of a subset of the population. However, the study did not involve direct testing of all individuals or record review of all individuals.

The U.K. study was an excellent first step to demonstrate, amongst other factors, the number of adult autistics and their living conditions.

There is nothing close to this in the United States. We can’t make real comparisons of prevalence between adults and children, for example. Not just because we don’t really have the data. Multiple studies have shown that when one tests adults, even those living in settings for the developmentally disabled, many autistics were unidentified before the study.

Here is the project description from the NIH Reporter website:

DESCRIPTION (provided by applicant): autism Spectrum Disorders (ASDs) are lifelong neurodevelopmental conditions with mostly unknown etiology that have a huge impact on affected individuals and their families, and are a major public health concern. This proposal, “autism Spectrum Disorder: Birth Cohort 1976-2000, Epidemiology and Adult Status,” in response to NIH Funding Opportunity Announcement (PA-10-158) describes an epidemiologic, population-based, large birth cohort study of ASDs. Significant gaps exist in the knowledge of ASD incidence and its possible rising trend. Detailed characterization (phenotype) of ASD incident cases and ASD subtypes [Autistic Disorder (AD), Asperger’s Syndrome (AS) and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS] is sparse, and potential risk factors (etiologies) are still unknown. Knowledge about adult outcomes of incident ASD cases identified in childhood is almost non-existent. ASD-associated medical costs are high, yet information to improve cost-effective medical management is lacking. A unique set of circumstances, including an already established population-based birth cohort of all children born 1976-2000 to mothers residing in Olmsted County, MN (N=43,934), access to complete, detailed school records for each child in the birth cohort (Independent School District ISD #535 – 41 public, private, home schooled), access to detailed medical records for every child in the birth cohort (Rochester Epidemiology Project-REP; NIH-AR30582), and the Olmsted County Healthcare Expenditure and Utilization Database (OCHEUD) provide the infrastructure to enable the successful completion of this project. This rigorous epidemiologic study involves an experienced multi-disciplinary research team, confirmation of the availability of documented behavioral symptoms of ASD from 1976 forward, with development of a detailed dictionary of descriptive phrases abstracted from medical/school records congruent with DSM-IV-TR criteria (pilot data) and a unique population-based birth cohort. [To help control for changes in special education laws and DSM criteria] this proposal will implement a systematic page by page review of medical and school records of all potential ASD cases regardless of initial school and medical classification and will apply the same uniform research criteria for ASD incident case identification (including DSM-IV-TR criteria), during the 37year study period. We will study the putative rise in incidence of ASD over 37 years, the possible role of certain risk factors on any incidence trend of ASD over time, the “shared risk” hypothesis by estimating the interaction between perinatal risk factors and family history (parents, siblings) of psychiatric disorders, assessing adult ASD current status and outcomes and cost effective medical management analyses. The knowledge achieved through this combined retrospective and prospective epidemiologic approach will substantially advance scientific/clinical knowledge about ASD

The methodology is similar to that of the CDC reports like the recent 1 in 88 study. The researchers will perform a records review. If the studies on children are any indication, many autistics will be identified through the records review.

This is not the same as a whole population study, where all individuals are screened and many tested for autism. Such a study was performed in Korea recently and resulted in a prevalence of 1 in 38, much higher than found elsewhere with non-whole population studies.

This begs the question of when someone will start a full-population study of adult autistics in the U.S. and, more importantly, what we might find from such a study.

Maternal Metabolic Conditions and Risk for Autism and Other Neurodevelopmental Disorders

9 Apr

A study from the U.C. Davis MIND Institute was published today in the journal Pediatrics: Maternal Metabolic Conditions and Risk for Autism and Other Neurodevelopmental Disorders. The link is to the abstract, but the full paper is available free for download.

The paper is part of the CHARGE Study. (CHARGE: Childhood Autism Risks from Genetics and the Environment). The study looked for increased risk of a child being diagnosed autism if the mother had metabolic conditions during pregnancy. The metabolic conditions studied were diabetes, hypertension and obesity. They found a possibly heightened risk of autism for these pregnancies. I wrote a more in-depth summary which is available at the Autism Science Foundation blog .

Woot! Autistics and Thinking Person’s Guide to Autism editor quoted in New York Times

8 Apr

A story out today by Amy Harmon of the New York Times, The Autism Wars, takes on some of the discussion ongoing about the new prevalence numbers out from the CDC. It is well worth the read.

What caught my eye, as one could tell from the title of this article, are paragraphs like these:

But Zoe Gross, 21, whose autism spectrum disorder was diagnosed at age 4, says masking it can take a steep toll. She has an elaborate flow chart to help herself leave her room in the morning (“Do you need a shower? If yes, do you have time for a shower?”). Already, she had to take a term off from Vassar, and without her diagnosis, she says, she would not be able to get the accommodations she needs to succeed when she goes back.

and

Those numbers are, of course, dependent on the definition of autism — and the view of a diagnosis as desirable. For John Elder Robison, whose memoir “Look Me in the Eye” describes his diagnosis in middle age, the realization that his social awkwardness was related to his brain wiring rather than a character flaw proved liberating. “There’s a whole generation of people who grew up lonelier and more isolated and less able to function than they might have been if we had taken steps to integrate them into society,” he said.

and:

“The term has become so diffuse in the public mind that people start to see it as a fad,” said Emily Willingham, who is a co-editor of “The Thinking Person’s Guide to Autism.” “If we could identify individual needs based on specific gaps, instead of considering autism itself as a disorder, that would be preferable. We all have our gaps that need work.”

In the past, many media outlets would (a) fail to seek autistic input and (b) seek input from autism parents with rather strong political agendas. Amy Harmon has been writing about autism for the Times recently and has articles focused on autistics, so I am not surprised by the tone of this article. But I do see this as a step forward in American Media coverage of autism news.

(note: I know three editors from the Thinking Person’s Guide team and have met Mr. Robison).

Autism Prevalence: More Affected or More Detected?

29 Mar

Tom Insel, director of the U.S. National Institute of Mental Health and Chair of the Interagency Autism Coordinating Committee has published a blog article coinciding with the CDC announcement of 1 in 88 estimated prevalence.

As a government publication, I feel it is OK to copy it here in total, but you are encouraged to read it on the NIMH website: Autism Prevalence: More Affected or More Detected?

Autism is always surprising. Earlier today, the CDC released new numbers from their ongoing surveillance of autism prevalence, the Autism and Developmental Disability Monitoring (ADDM) Network. What was once considered a rare disorder is now reported as affecting 1 in 88 children, 1 in 54 boys. These new numbers, up 78 percent from 2002 and 23 percent from 2006, raise immediate questions. Are more children affected or more detected? Does the increase reflect a growing problem, or do these new numbers reflect an improvement in our ability to diagnose and serve those affected?

These new data do not answer these questions. The CDC surveillance project focuses on 8-year-olds identified in 2008; that is, children who were born in 2000. By definition, autism begins before age 3, so a focus on 8-year-olds should capture anyone who was identified and still has a diagnosis. The prevalence numbers are based on a standardized assessment of descriptions of behaviors culled from administrative or health records from select communities, not on standardized diagnostic interviews in the general population. The strength of this approach is its wide reach, allowing a comparison across 14 states. The CDC reports a four-fold variation across sites. These new results, as with those from other records-based surveillance systems, do not answer questions related to why the identified prevalence of autism has changed over time.

Other research suggests a complicated picture. A total population study of all 7–12-year-olds in a town in South Korea (more than 55,000 children) used standardized diagnostic instruments for children who screened positive and reported a prevalence of 2.64 percent.1 That is 1 in 38 children! There is no reason to expect that this prevalence is unique to this community. To be sure, two-thirds of these children had never received a diagnosis of autism spectrum disorder (ASD), meaning that the identified prevalence was closer to 1 percent or one in 100, roughly the same prevalence reported in the United States. From this perspective, the increase reported by the CDC might mean we are better at detecting children who meet criteria for ASD, but potentially we still are only halfway to the actual prevalence in the general population. Indeed, the biggest increase in the CDC surveillance report was in Hispanic and African American children, groups which previously had low rates of detection.

But can we be certain that more children are not affected? Data from the Developmental Disability Services registry in California demonstrates a 12-fold increase in the number of children receiving services for autism over the past 20 years, with a continuing rise recently. But these data, while dramatic, cannot rule out increased use of the diagnosis. Bearman and colleagues who have studied the California trends suggest that only about 26 percent of this increase can be explained by diagnostic substitution, especially for the most severe cases — children with intellectual deficits — which may not have been identified as autism in an earlier era. Another fraction can be attributed to better ascertainment or detection especially for children at the less severe end of the spectrum. Together these factors explain only a part of the linear increase observed in the California registry. In the absence of other explanations they and others suggest that a real increase is quite likely.2, 3, 4

Which makes a recent report from England especially surprising. In a careful epidemiological study based on a national sample (n = 7,461 adults) from 2007, Brugha and colleagues did careful diagnostic assessments based on standardized interviews. They found that familiar rate of about 1 percent in adults across the entire age range without a significant reduction in the older part of the sample as one would expect if the prevalence had increased in recent years.5

This takes us back to the central question: has the number of children with ASD increased or not? Total population epidemiological studies suggest much or all of the increase is due to better and wider detection. Studies of administrative and services data suggest that better detection cannot fully explain the profound and continuing increase. Are we seeing more affected or more detected? The question is vitally important, but there is not one, simple answer just as autism is not a single, simple disorder.

If there is an increase in the number affected, then we need to find the causal factors to bend the curve. Analogous increases in food allergies, asthma, and Type 1 diabetes have provoked an aggressive search for environmental causes. If the number of children with ASD has not changed, but we are diagnosing and serving 12-fold more of them over the past two decades, then we need to focus on better diagnosis and treatments rather than looking for new environmental factors driving the precipitous increase.

Science can resolve this dilemma, but the methods to examine this question as well as the answers will be complex. While it is never possible to go back in time, longitudinal population based studies and even careful retrospective studies can determine if more children are affected and if the nature of the disorder is changing over time. The changes in prevalence of other developmental disorders, measured with biomarkers (Type 1 diabetes) or emergency room visits (food allergies), appear to be true increases in the number of children affected. As diagnostic changes and ascertainment fail to explain the majority of the increase in autism prevalence, it seems prudent to assume that there are indeed more children affected and continue an aggressive search for causes while striving to improve detection, treatments, and services. Our working assumption is that there are both more children affected and more detected.

References

1Kim YS, Leventhal BL, Koh YJ, Fombonne E, Laska E, Lim EC, Cheon KA, Kim SJ, Kim YK, Lee H, Song DH, Grinker RR. Prevalence of autism spectrum disorders in a total population sample. Am J Psychiatry. 2011 Sep;168(9):904-12. Epub 2011 May 9. PubMed PMID: 21558103.
2King M, Bearman P. Diagnostic change and the increased prevalence of autism. Int J Epidemiol. 2009 Oct;38(5):1224-34. Epub 2009 Sep 7. PubMed PMID: 19737791; PubMed Central PMCID: PMC2800781.
3Keyes KM, Susser E, Cheslack-Postava K, Fountain C, Liu K, Bearman PS. Cohort effects explain the increase in autism diagnosis among children born from 1992 to 2003 in California. Int J Epidemiol. 2011 Dec 7. [Epub ahead of print] PubMed PMID: 22253308.
4Bresnahan M, Li G, Susser E. Hidden in plain sight. Int J Epidemiol. 2009 Oct;38(5):1172-4. PubMed PMID: 19797336.
5Brugha TS, McManus S, Bankart J, Scott F, Purdon S, Smith J, Bebbington P, Jenkins R, Meltzer H. Epidemiology of autism spectrum disorders in adults in the community in England. Arch Gen Psychiatry. 2011 May;68(5):459-65. PubMed PMID: 21536975.

Vaccine-autism groups jump embargo on CDC prevalence

28 Mar

The CDC will soon release new autism prevalence estimates. This much has been discussed online for some time since Disability Scoop published CDC Set To Release New Autism Numbers on March 9.

The “Canary Party” has put out a couple of press releases. One “New CDC Autism Numbers Coming Soon; Rate Increase to Over 1 in 100 Expected by The Canary Party ” and another (which appears to be submitted twice) “The Canary Party Expects CDC to Announce New Autism Rate of 1 in 88, and Believes CDC Likely to Declare “No Public Health Emergency” and “No Epidemic”” The Canary Party is an offshoot of the autism-is-caused-by vaccine organizations like SafeMinds (whose Mark Blaxill is quoted in the press releases).

Also, A-Champ sent out an email alert along similar lines.

These groups appear to be vying for media attention. By getting their press releases out before the embargo is lifted, they might be in a position to get media organizations to contact them for quotes.

It is not the most ethical way to obtain media attention. It also isn’t really that effective. One can tell this because, it didn’t work last time. Yes, multiple groups broke the embargo for the 1% prevalence estimate which came out in the journal Pediatrics in 2009. This was discussed at length here at Left Brain/Right Brain in Autism rate of 1 percent, and the embargo that wasn’t. The media discussed not the talking points of these groups, but the broken embargo. See When News Breaks On Autism, Who Gets It Out First? and Autism news raises question: When is an embargo not an embargo?

Interestingly, the Canary Party press release doesn’t mention mercury, thimerosal or vaccines. Just “The only plausible explanation for these rapid increases is a change in the environment affecting millions of American children” Which ignores a great deal of work published in the last 10 years, especially that of Prof. Peter Bearman’s group at Columbia which has quantified some of the social factors behind the increases observed.

For those who haven’t heard of the “Canary Party”, you are not alone. It is a small (under 5,000 facebook “likes”. Compare that to over 315,000 for the Democratic Party, or over 1 million likes for Autism Speaks).

Autism News Beat has also discussed the broken embargo in Embargo? What embargo?

note: I edited this article after publishing to complete an incomplete sentence in the first paragraph.

Why the next CDC autism rates spells bad news for the mercury hypothesis

22 Mar

A recent article on Disability Scoop discussed an upcoming CDC autism report. The MMWR’s(Morbidity and Mortality Weekly Reports) from the CDC have been one of the standards for autism prevalence for years. Each CDC prevalence estimate is calculated for a group of 8 year olds born in a certain year. For example, the last estimate was “Prevalence of Autism Spectrum Disorders — Autism and Developmental Disabilities Monitoring Network, United States, 2006” for children born in 1998.

Every time a new CDC autism MMWR has come out, the prevalence estimates are higher. Every timer there are groups that point to the rising number of vaccines and mercury exposure from those vaccines. People point out that there is a correlation between mercury exposure (thimerosal) and the autism rates. The MMWR’s so far have been all for children born in the 1990’s, a period when the number of vaccines and the thimerosal exposure from those vaccines was increasing.

Here are the autism prevalence estimates from recent CDC reports:

2006 (birth year 1998) 9 per 1000
2004 (birth year 1996) 8 per 1000
2002 (birth year 1994) 6.6 per 1000
2000 (birth year 1992) 6.7 per 1000

Following this trend, the next report will be for children born in 2000, age 8 in 2008. From the perspective of testing the vaccine hypothesis, in particular the mercury/thimerosal hypothesis, this is the start of a new era. In 1999 the AAP recommended that thimerosal be removed from vaccines. By 2001, all infant vaccines with the exception of influenza were produced only in thimerosal-free versions. This means that children born in 2000, the cohort the CDC will likely report upon, received, on average, a lower exposure to thimersal than the previous groups.

If the mercury hypothesis were correct (and there already a great deal of evidence to say that it is *not* correct) the autism rate should go down. At the very least, it should stay the same as the group before–about 0.9%.

Of course we will hear claims like “but not all the thimerosal containing vaccines were gone for this group” and “but what about the influenza vaccine?” and more obvious excuses in case (at it seems likely) the prevalence goes up again.

All of these avoid the fact that the average thimerosal exposure will be much lower for this group than the previous (1998 birth year) group. The excuses amount to…well…how about a visual?

With thanks to Reuters for the image I am using.

Yes, goal posts will move. Nice idea putting them on wheels. Could save a lot of effort, but those promoting the mercury idea are already used to moving goalposts.

And what if the CDC also reports on birth year 2002 (they have reported two birth cohorts at the same time in the past)? Those goalposts might to have to move quite a bit.

Now consider a different perspective. Consider that each CDC report has been an undercount. They don’t do a “whole population” survey like was done in Korea recently. They don’t test all children, they rely upon records already in existance. The last CDC report found that about 23% of the children identified as autistic in the study did not have a diagnosis before the study. Clearly the United States has not been identifying all the autistics in the population. Given this, the rising autism prevalence estimates (and, yes, they are *estimates*) could be seen as an accomplishment. This is a position put forth by Prof. Richard Grinker. The rising prevalence estimates reflect a the U.S. getting better at identifying the autistic students in our schools.

CDC Set To Release New Autism Numbers

16 Mar

Disability Scoop has an article: CDC Set To Release New Autism Numbers. This was posted last week, and it starts:

The Centers for Disease Control and Prevention are expected to unveil a new autism prevalence estimate as early as this month.

The agency currently says that 1 in 110 children have autism, a figure first released in late 2009. Now, less than three years later, the CDC is set for an update.

I had heard rumors that the next prevalence estimate would be much higher. Not higher than the Korean prevalence numbers, but a significant jump. But–I heard these rumors together with the prediction that the estimate would come out last year. So, rumors are worth what you pay for them.

Autism recurrence in half siblings: strong support for genetic mechanisms of transmission in ASD

5 Mar

Autism recurrence in half siblings: strong support for genetic mechanisms of transmission in ASD comes out of Dan Geschwind’s group at UCLA. They used the Interactive Autism Network database. Here is the abstract:

Current estimates of the heritability of autism spectrum disorders (ASD) derived from existing clinical twin studies1, 2, 3, 4 are potentially confounded by a number of factors, including low sample size, inconsistency in case definition and the role of de novo mutation (currently estimated to contribute to some 20% of cases), and the possibility that heritable causes of ASD in a twin could result in environmentally engendered affectation of a non-identical co-twin in utero, especially if mediated by humoral or immune mechanisms. To minimize these confounds, we compared autism recurrence in half siblings versus that in full siblings, using data (6 June 2011) from over five thousand families enrolled in the Interactive Autism Network (IAN), a national volunteer register for ASD, detailed characteristics of which have been previously described by our group. Recurrence rate among full siblings was observed to be approximately twice that among half siblings, providing strong evidence of genetic transmission of ASD.

The recurrence risk is the chance that a sibling has autism if another sibling does. The authors found the recurrence risk to be twice as high for full siblings, which is consistent with a primarily genetic model of autism risk.

This follows on a number of recent twin studies (here, here and here) have shown a lower concordance than previously estimated and the baby siblings study which showed a 19% recurrence risk for autism.

I wonder at how many half-siblings there are in the cohort. A small subpopulation could mean large error bars.

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