LateB unit infant mortality rise ‘not extreme’ – inquiry

The rise in the number of deaths at the neonatal unit where Lucy Letby murdered babies in 2015 was “not high enough” to warrant an external inquiry, a public inquiry has found.

Sir David Spiegelhalter, Emeritus Professor of Statistics at the University of Cambridge, gave evidence about the death toll at the Countess of Chester Hospital, where Nurse Letby attacked and killed children.

The Thirlwall Inquiry, set up to investigate the circumstances surrounding Letby’s crimes, heard that there were eight deaths in 2015 and five deaths in the first half of 2016. Only between one and three deaths occurred per year between 2010 and 2014.

Assessing the 2015 figure, Sir David said: “Generally this would be considered high enough to trigger an alert and someone should look at it locally, but not so extreme as to be considered an outlier.”

Letby, now 35, began working at the Countess of Chester Hospital in January 2012 and murdered seven children between June 2015 and June 2016.

The nurse, originally from Hereford, has also been convicted of the attempted murder of seven other babies.

Sir David told the public inquiry that he expected to see a “signal” at least once a year “by chance alone” in one of the UK’s 150 neonatal units – such as the 2015 mortality for the Countess of Chester. figure of.

He added, “They are small numbers but just because the numbers have increased does not mean there is any particular reason for it, and so it should be investigated.”

The experienced statistician explained that outliers were “something that you are absolutely sure is not just normal variation… there is some specific reason behind it”.

Sir David pointed out that no statistical monitoring system could reveal the reason or reasons why something happened.

A classic example of statistical outliers, he said, occurred at Bristol Royal Infirmary in the 1980s and 1990s, which revealed failures in pediatric heart surgery.

Sir David, who led a team of statisticians for the subsequent public inquiry, said there was “clear water” between Bristol and 11 other centres.

This was not the case for the Countess of Chester Hospital’s neonatal unit, he said.

Sir David said its mortality rate in 2015 and 2016 was only 10% higher than the average for neonatal units with similar birth rates.

He said that the Countess of Chester was supreme in the level of her consorts, but “only fair”.

“No one would call it an outsider,” he said.

Letby is serving 15 life sentences after being convicted at Manchester Crown Court of the murders of seven infants and the attempted murders of seven others, including two attempts on one of the victims.

The public inquiry, chaired by Lady Justice Thirlwall, is hearing the final week of evidence in Liverpool Town Hall.

Their findings are expected to be published in the autumn.

Additional reporting by the Press Association.