WASHINGTON, United States (AFP) — African-American children in the United States have a 3.5 times greater risk of dying from an operation than white kids, according to a study out Monday based on tens of thousands of children.

Researchers at Nationwide Children’s Hospital in Ohio focused exclusively on children who were relatively healthy at the time of the operation, without chronic diseases or other health risk factors known as “comorbidities” that black people in the United States statistically have in a higher number compared to white people.

In the study, published in the journal Pediatrics, the researchers wanted to see whether there was any difference in post-operative conditions even among apparently healthy patients.

The answer is yes, based on a study of 172,549 children between 2012 and 2017.

Very few of the children — 23 white and 13 black — died within 30 days of their operation, according to data from 186 medical centres.

However proportionally, the mortality was 0.02 per cent among white kids, and 0.07 per cent — or 3.5 times higher — among black children.

Researchers also found that black children were more likely to experience post-operative complications — 16.9 per cent against 13.8 per cent for white children — as well as serious adverse events such as cardiac arrest or re-operation.

The authors mention several possible reasons, medical, social, and economic, as race is still closely linked to socioeconomic status in the US.

These include a higher likelihood of African Americans to develop post-surgical complications, according to previous studies; physician-patient communication; health care provider bias; poverty; and limited access to health care.

Black children may also be treated in lower-quality hospitals, as those are often the ones available where many of them live.

It’s also possible that doctors are less willing to recognise a medical problem in black patients than white ones, as other studies have shown, especially when it comes to patients reporting pain.

As is often the case in this type of large studies the authors do not conclude on a cause and effect relationship, but believe the problem has multiple causes.

“These results may help guide preoperative discussions about risks and may guide authors of future studies to elucidate the mechanisms underlying racial differences in post surgical outcomes in children,” they conclude.