Monday, 23 January 2017

Autism diagnoses (and diagnostic stability) in Germany

"From 2006 to 2012, the prevalence of autism spectrum disorder diagnoses in 0- to 24-year-olds increased from 0.22% to 0.38%."

That was one of the details included in the rather interesting paper by Christian Bachmann and colleagues [1] who provided some introductory information on the the trends in autism diagnoses in Germany. I say 'introductory information' because it appears that autism or autism spectrum disorder (ASD) has not exactly received the research attention in Germany that it perhaps has in other similarly developed nations such as the United States or here in Blighty. Indeed, as Bachmann et al note: "Due to the only available study to date, the prevalence of ASD in Germany is estimated to be about 0.25% in 0- to 24-year-olds in 2009" and even that was taken from another study by the author [2].

This time around, the authors listed two primary aims for their research: (a) "to establish the time trends in the administrative prevalence of autism spectrum disorder diagnoses" and (b) "to assess the stability of autism spectrum disorder diagnoses over time." I'm interested in both these areas on this blog (see here for example). Data for the time trends part of this research came from "the German statutory health insurance company Allgemeine Ortskrankenkassen (AOK) from the years 2006 to 2012" where a diagnosis of ASD was registered by ICD-10 definition. Data for the stability side of their research was via a "cohort with a first-time diagnosis of autism spectrum disorder in 2007 through 2012, investigating the percentage of retained autism spectrum disorder diagnoses."

Results: well as per the opening sentence to this post, the only way is up when it comes to the estimated prevalence of autism or ASD despite the figures being a tad lower than those for other countries. Those percentages were based on nearly 15,000 ASD diagnoses being recorded in 2006 out of 6.9 million insurees, and nearly 22,000 ASD diagnoses in 2012 out of 6.4 million insurees. Males were quite a bit more likely to be diagnosed with autism/ASD and prevalence peaked for the age group 6-11 year olds.

Then to that stability part of the study and from "3927 patients (mean age: 8.7 years, 68.9% males)" with a specific ASD diagnosis in 2007 only a third 'carried on' with a specific diagnosis by 2012. The authors note: "This figure is lower than the usual persistence for ASD diagnoses, which is about 73%–100%." Lower? Yes, I'd say. The reasons for this quite notable lack of diagnostic stability? Well, the authors note that there is probably going to be more than one (before anyone makes any sweeping generalisations). They talk about the lack of "specialised mental health services that are competent to diagnose ASD according to international standards and guidelines" as one factor. They talk about diagnoses "often made by paediatricians or occupational therapists, without employing diagnostic gold standards like Autism Diagnostic Observation Schedule (ADOS)." They even talk about diagnostic switching between ASD subgroups as potentially also being a factor to consider. And then another possibility: "Other reasons include improvement of symptoms because of successful therapeutic interventions" without any specific mention of what types of therapeutic intervention might be involved. Sounds very 'optimal outcome' to me (see here). In short, it's probably going to be complicated.

Bearing in mind those diagnostic stability figures and the authors reliance on a database that relied on those unstable figures for prevalence estimates, this is interesting research. It shows that even a social and economic powerhouse like Germany still has some way to go in many areas not least with that related to autism. Where next? Well, as per the authors suggestion: "one possible option could be to establish standardised diagnostic algorithms and certify ASD diagnostic centres who employ these standards." Sounds good but in amongst the chatter about autism 'misdiagnosis' and seemingly 'ill-trained' professionals diagnosing, I do wonder whether further, more detailed, investigations are needed on the autism diagnostic stability figures of Germany and whether it's all just due to administrative errors...

Music to close, and this guy was/is apparently quite big in Germany...  Permit denied!

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[1] Bachmann CJ. et al. Diagnoses of autism spectrum disorders in Germany: Time trends in administrative prevalence and diagnostic stability. Autism. 2016. Dec 20.

[2] Bachmann CJ. et al. Psychopharmacological treatment in children and adolescents with autism spectrum disorders in Germany. Res Dev Disabil. 2013 Sep;34(9):2551-63.

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ResearchBlogging.org Christian J Bachmann, Bettina Gerste, & Falk Hoffmann (2016). Diagnoses of autism spectrum disorders in Germany: Time trends in administrative prevalence and diagnostic stability Autism: International Journal of Research & Practice : 10.1177/1362361316673977