Questioning Answers: Poverty status and autism, ADHD and asthma

Friday 3 March 2017

Poverty status and autism, ADHD and asthma

The paper by Christian Pulcini and colleagues [1] talking about poverty status potentially influencing "parent-reported lifetime prevalence and comorbidities" when it comes to three target conditions (autism, attention-deficit hyperactivity disorder [ADHD] and asthma) should have been a call to action. Concluding that "poor and near poor children had a higher lifetime prevalence of asthma and ADHD, but not ASD [autism spectrum disorder]" [2], some of the findings have instead attracted criticism based on the content of the abstract (see here); specifically the line: "the lifetime prevalence of ASD rose almost 400%."

Poverty and diagnosis is a topic that I've covered before on this blog (see here for example) and how not every research study has linked poverty (measures of poverty) to something like autism and/or ADHD. At least that is, when taking into account "elevated emotional problems among children with ASD + ADHD" [3].

On this most recent occasion, Pulcini et al drew on data derived from the "National Survey of Children's Health [NSCH] for years 2003, 2007, and 2011-2012" and specifically "trends in parent reported lifetime prevalence and comorbidity among children with asthma, ADHD, and ASD" taking into account variables like poverty status. The NSCH initiative has again, been talked about previously on this blog (see here and see here) in terms of parent-reported prevalence of autism and parent-reported epilepsy appearing alongside autism. It's a good rough-and-ready measure of what estimated prevalence rates might look like (with the need for further, more detailed study).

This time around the authors illustrated that - yet again - the only way is up when it comes to estimated prevalence rates for all the 'target' conditions examined. I don't think anyone should be too surprised at such findings given data from other studies in other geographic areas (see here) specifically with the autism spectrum in mind. I'm not going to head into the debate about whether the 400% increase figure is right or wrong but will note previous findings [4] that suggested that: "differential survey measurement error over time was not a major contributor to observed changes in the prevalence of parent-reported ASD. Rather, much of the prevalence increase from 2007 to 2011–2012 for school-aged children was the result of diagnoses of children with previously unrecognized ASD." This for when data from the 2007 and 2011-2012 surveys were contrasted (not the 2003 survey).

The contribution of poverty or near poverty was not to be sniffed at when it comes to those ADHD and asthma diagnoses. This is perhaps even more important when one considers that these two labels might be rather more 'entangled' than many people might have previously realised (see here). That a poverty and ADHD link might also generalise to somewhere like here in the UK is also worth noting (see here) and implies that quite a bit more research is needed to answer the question: why? With regards to autism (ASD), the observation that the "rise in ASD was associated with being nonpoor"adds to an on-going debate, with some studies saying yes, we agree, and other studies saying no, we don't (see here). In short, it is slightly more complicated when it comes to how social factors might affect autism rates.

Music: Three steps to heaven.

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[1] Pulcini CD. et al. Poverty and Trends in Three Common Chronic Disorders. Pediatrics. 2017 Feb 13. pii: e20162539.

[2] Dreyer BP. Congress Should Adopt a “Do No Harm to Children” Standard in Changes to Public Health Insurance. Pediatrics. 2017. Feb 2017.

[3] Flouri E. et al. Poverty and the Growth of Emotional and Conduct Problems in Children with Autism With and Without Comorbid ADHD. J Autism Dev Disord. 2015 Sep;45(9):2928-38.

[4] Blumberg SJ. et al. Changes in Prevalence of Parent-reported Autism Spectrum Disorder in School-aged U.S. Children: 2007 to 2011–2012. Natl Health Stat Report. 2013 Mar 20;(65):1-11.

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