# I was quoting the statistics, I wasn't pretenting to be a statisitcian

In defence of Roy Meadow

Lancet, Vol 366, July 2,2005

Richard Horton (editor of Lancet)

Beyound reasonable doubt

Plus Magazine, 2002

Helen Joyce

Muliple sudden infant deaths--coincidence or beyound coincidence

Paediatric and Perinatal Epidemiology 2004, 18, 320-326

Roy Hill

Sir Roy Meadow is a paediatrician who is well known for his research in child abuse. In 1999 two of Sally baby boys died. The first death was first recordered as a natural cot death. But after her second baby boy died she was tried and convicted of murdering both of her children and given a lifetime sentance.

Roy Meadow testified in her trial stating that chance of two natural cot deaths was 1 in 73 million suggesting that two natural cot deaths was beyond belief. This estimate came from a study called the "Confidential Inquiry for Stillbirths and Deaths in Infancy" (CESDI). This study gave detailed information about the deaths of all babies in five regions of England between 1993 and 1996. This study estimate that the chance of a cot death was 1 in 1,303. But if the child was from an afluint non-smoking family with the mother aged over 26, then the chance decreased to 1 in 8,543) Since Sally Clark was in the this group, Meadow assume the chance of the first child was a cot death was 1/8,543 and squaring this he obtained the 1 in 73 million estimate for the chance of two cot deaths.

Of cource, soon after the trial it was pointed out that this multiplication assumed independence of the two events which surely would not be the case. In fact IEnviornment, biological and genetic factors would suggest a lower probability for the second child. Then it was pointed out that this was a classic case of the Prosecurers Paradox which in the case of DNA fingerprinting has been officially recognized by the courts in England. Applied to this cased it means Meadow is estimaing the probability that two randomly chosen babies both are victims of cot deaths when the jury is interesting knowing

There were conflicts in the medical testimony and one has to assume that Meadow 's 1 chance in 73 million played a large role in the juries verdict.

Meadow justified his 1 in 73 million by saying that a a report of a