The father of a baby poisoned by nurse Beverley Allitt in 1991 has warned that hospital authorities ignored similar warning signs during Lucy Letby's crimes more than two decades later. An inquiry into Letby's murders concluded that some of the seven infants she killed might have survived had warnings from the Allitt case been heeded. David Crampton's wife suspected something was amiss with their five-month-old son Paul during his hospitalisation, but staff appeared unable to manage the crisis effectively.

Paul was admitted to Grantham and Kesteven Hospital in March 1991 with a chest infection and suffered three unexplained collapses from insulin poisoning. Pathology reports showed his blood contained 43,147 milliunits of insulin—among the highest levels ever recorded—compared to normal readings of 10 to 13 units, suggesting Allitt had injected an entire adult syringe. Allitt attacked 13 children over 59 days, killing four and receiving 13 life sentences in 1993, whilst Letby murdered seven infants and attempted to murder seven more between June 2015 and June 2016, with the cases showing striking parallels.