January 9, 2015

expert reaction to ritual circumcision and autism

Researchers publishing in the journal Journal of the Royal Society of Medicine have reported an association between ritual circumcision and autism, stating that the risk of autism spectrum disorder was increased for boys who underwent circumcision.

Prof. Jeremy Turk, Consultant Child & Adolescent Psychiatrist, Southwark Child & Adolescent Mental Health Neurodevelopmental Service, said:

“The findings of this research, whilst interesting, need to be considered carefully – one cannot draw very strong conclusions from the data. This is not a causal study, but instead compares data sets and looks for correlations. Whilst this is a valid way of doing a study, it means that we must be careful about any implications.

“For example, many cases of autism are missed until children are older and as there are relatively few cases of autism this could easily skew the data. The rate of identified autism spectrum disorders (ASD) in the early circumcision group was less than 1.5%, i.e. well within the general population rates for ASD (1-2% at least).

“Furthermore, there are many potentially confounding variables which could explain raised ASD rates, which the authors do not explore or account for.

“Finally, I have some issues with the premise in that their speculations regarding early pain as a cause of autism are, to say the least, highly speculative!

“Therefore the findings of this study, and their interpretation, should be treated with extreme caution.”

Prof. Kevin McConway, Professor of Applied Statistics, The Open University, said:

“This study raises an interesting question, but one that cannot be fully answered with these data.

“The study is observational, and in such studies it’s always tricky to tell what causes what. The observed increase in risk of autism spectrum disorder (ASD) in circumcised boys might be due to the circumcision, or it might not. Religions that prescribe circumcision prescribe other things too, such as diet or clothing. Perhaps differences in diet or clothing lead to the increased ASD risk, rather than the circumcision. Cultural and family differences may be crucial.

“The researchers try to deal with this issue in two ways, but in my view neither is completely satisfactory.

“They record ‘cultural background’ and allow for that in the analysis. But the fact that they label some families as ‘Muslim’ doesn’t mean that they are actually Muslim. It means that the boy in question had at least one parent or grandparent who was born in one of 17 predominantly Muslim countries. So the family may be Muslim, or it may not. The researchers don’t know which families are Muslim – they merely have a rough idea. There will be important differences between families that would be missed even if we did know exactly who was Muslim, but this vagueness makes things worse.

“The researchers tried to deal with these differences further by investigating whether the sisters of circumcised boys had an increased risk of ASD. The idea is that family influences should work in the same way in the sisters as in their circumcised brothers, so if the increased risk in the boys is due to something about their families, it should show up in the sisters too.

“But I think there are problems here too. First, it’s well known that girls and boys differ in ASD risk, so perhaps things just work differently in girls in relation to ASD.  Then, they compared the sisters of circumcised boys with all other girls, not just those with an uncircumcised brother. Perhaps the mere fact of having a brother has some impact on ASD risk, so this may not be a fair comparison. They measured the risk of a having a circumcised brother as starting at the date of circumcision, whereas if it’s due to family circumstances, those are unlikely to change at the moment of circumcision. Finally, they did actually find an increased ASD risk in the sisters – the increase was not statistically significant, but ‘not statistically significant’ means that the increase might have been zero, not that the increase IS definitely zero. So including the girls does not get round the problems at all, in my view.”

Dr Rosa Hoekstra, Lecturer in Psychology, The Open University, said:

“I think this is an extremely speculative study that needs very careful handling in the popular media. The study is purely based on register data and takes a registered autism diagnosis at face value, without considering cultural or social factors affecting the likelihood of an (early) autism diagnosis. Even in a high income country like Denmark not all children with autism are detected and given a suitable autism diagnosis at an early age (the age under study in this paper).

“This study tries to implicate a link between ritual circumcision and the risk for autism. Important to note is the data used in the analyses: The authors linked autism diagnoses as recorded in the Danish public health system with whether boys had undergone circumcision in Danish hospitals or private clinics. Any boys undergoing circumcision outside the Danish medical system were left unaccounted for. Likewise, any children who may warrant an autism diagnosis but have not yet been formally diagnosed (with the diagnosis registered in the Danish health register) are disregarded.

“What the study suggests is that boys who have undergone circumcision by a medical professional are more likely to receive an autism diagnosis at a young age. The authors interpret these findings as suggestive of a causal link between the potential pain experienced due to the circumcision and a risk for autism. An entirely different but in my view much more plausible explanation is as follows: Boys with symptoms of autism who undergo circumcision by a medical professional may have their symptoms recognised as autism more often, and at an earlier age, than boys who are not circumcised and who may therefore fly under the radar of medical professionals. In other words: the detection rate of autism (rather than the risk of autism per se) may be higher in boys seeing a medical professional for circumcision.”

‘Ritual circumcision and risk of autism spectrum disorder in 0- to 9-year-old boys: national cohort study in Denmark’ by Frisch et al. published in Journal of the Royal Society of Medicine on Friday 9^th January. 

Declared interests

None declared