ByÂ
Topiramate, an antiseizure medication, when taken by pregnant women did not appear to increase the risk of their children developing autism spectrum disorder (ASD), according to the authors of a new study.
However, Brian Hooker, Ph.D., chief scientific officer at Childrenâs Health Defense (CHD), questioned the studyâs findings, and whether the researchers manipulated the data in a way to obfuscate a possible connection.
âThis study is fundamentally flawed,â Hooker â who has a child with autism â told The Defender. âIt just seems like they designed a study to not find things.â
Researchers at the Harvard T.H. Chan School of Public Health analyzed the health records of mothers with epilepsy who took topiramate, seeking to determine if the drug increased their childrenâs risk of autism.
Topiramate â sold by Johnson & Johnsonâs subsidiary Janssen Pharmaceuticals under the brand name âTopamaxâ â is also prescribed to treat migraines, bipolar disorder and weight management.
The researchers compared the mothersâ records with records from mothers with epilepsy who took two other antiseizure medications â lamotrigine and valproate sodium â and with records from mothers with epilepsy who did not take any antiseizure medication.
The researchersâ data, published March 21 in The New England Journal of Medicine, initially showed that kids who were exposed in utero to topiramate had an autism incidence rate of 6.2% at age 8 â 2% higher than that of children born to epileptic mothers who had not taken an antiseizure medication during pregnancy.
However, after adjusting their statistical model to account for other possible risk factors â called âconfounding variablesâ â that the researchers thought might be associated with both the use of anti-seizure medications and with ASD diagnosis in the baby, the data no longer showed that topiramate appeared to increase kidsâ risk of ASD when exposed prenatally.
Hooker criticized the methodology. He said researchers could have done whatâs called a case-control study to help them clearly assess if there was a relationship between topiramate and ASD, but they didnât do that.
Instead, the Harvard researchers did whatâs called a cohort study by looking at data records of nearly 4.3 million pregnant women and their children from 2000 to 2020.
They compared the autism rates between groups, or âcohorts,â such as the group of kids whose mothers had epilepsy and took topiramate during pregnancy, the group of kids whose mothers had epilepsy but did not take an antiseizure medication and the group of kids whose mothers didnât have epilepsy or take an antiseizure medication.
For this type of study design to produce meaningful results, itâs important that the cohorts are âbasically similar,â Hooker said.
But Hooker said the cohorts were âso poorly matchedâ that it was âimpossibleâ to draw a conclusion about topiramate and the prevalence of autism. âThis gave the authors an âoutâ as far as dismissing any relationship found between topiramate in pregnancy and ASD,â he said.
For instance, the moms with epilepsy in the topiramate group exhibited higher rates of smoking, illicit drug use and the use of other prescriptions compared to the moms in the group who had epilepsy but had not taken antiseizure medications.
The researchers could have controlled for these differences by dropping women who smoked or used illicit drugs from their dataset â and they still would have had a large enough sample size to get meaningful statistical results.
But they didnât do that, Hooker said. âInstead, they chose to âmodel their wayâ out of a relationship using many covariates that were not controlled for.â
In other words, the researchers âmuddied the watersâ by adding extra variables that they could blame for causing the increased risk of autism, he said, leaving topiramate off the hook.
âIt is really too bad,â Hooker said, because clear information about topiramateâs relationship to ASD is âso vital to have.â
The studyâs lead author, Dr. Sonia HernĂĄndez-DĂaz, disagreed with Hooker.
HernĂĄndez-DĂaz â who until 2023 was a methods consultant to Johnson & Johnson for pregnancy studies â told The Defender in an email that she and her team designed their study âto assess whether the anti-seizure medication had an effect on the risk of ASD.â
According to HernĂĄndez-DĂaz, the researchers did a cohort study rather than a case-control study because they âhad the opportunity to analyze the data as a cohort (i.e. use the full information) and because an ad hoc case-control study would be prone more to biases (e.g. selection of controls and recall bias of prenatal exposure).â
Hooker said he didnât agree with HernĂĄndez-DĂazâs assessment of case-control studies. âI think sheâs introduced biases in doing the cohort study instead.â
HernĂĄndez-DĂaz also said she and her team âdid try to create more homogeneity between treatment groups by adjusting for many factors.â
When asked why they did not eliminate women who smoked or used illicit drugs from their dataset so they could make cleaner comparisons, HernĂĄndez-DĂaz said that a randomized clinical trial on antiseizure medications would not be restricted to non-smokers…
READ FULL ARTICLE HERE… (childrenshealthdefense.org)
Home | Caravan to Midnight (zutalk.com)
Be First to Comment