Abstract
Morris and Wiswell express concern over small numbers of circumcised boys with autism spectrum disorder (ASD) and hyperkinetic disorder in non-Muslim families, apparently unaware of the fact that our findings were statistically significant despite the limited statistical power of these analyses, not because of it. Also, without substantiation, our critics consider the overall proportion of boys in Muslim families who were ritually circumcised by Danish doctors (10.9%) ‘improbable’, although no one knows the exact proportions of ritual circumcisions performed by doctors vs. religious circumcisers in these boys. As explained, 1 any mischaracterisation of boys as intact as opposed to circumcised would likely be non-differential, leading to conservative, not exaggerated, risk estimates.
We did not dredge medical records searching for adverse effects of circumcision. Rather, using national data, we tested the a priori hypothesis that ritual circumcision might be associated with an increased risk of ASD, based on converging evidence from animal, clinical and ecological studies. Morris and Wiswell’s speculations about urinary tract infections and general anaesthesia in infants do not address our research question of whether circumcision is linked to an increased risk of ASD; and the paracetamol hypothesis was discussed in our article.
Morris and Wiswell claim that our study was ‘flawed’, but they do not provide relevant reasons for concern that were not already addressed in our original study.