Letter from Len Cook to Mrs. Curtis-Thomas, dated 9 July 2003:

As National Statistician, I have been asked to reply to your recent question asking how many people in (a) the UK and (b) Sefton died from a head injury in the past 10 years. (124103)

Figures for England and Wales and Sefton local authority are provided in the following table. Comparable data for the United Kingdom are not available during this period as mortality by specific type of injury is not available for Scotland prior to 1996.

The figures shown are the numbers of deaths where head injury was assigned as the main injury sustained by the deceased when an accident or violence initiated the train of events leading directly to death.

¹ Head injuries were defined using the International Classification of Diseases, Ninth Revision (1CD-9) codes N800 to N804 and N850 to N854 for the years 1993 to 2000 and, for the years 2001 and 2002, the International Classification of Diseases, Tenth Revision (1CD-10) codes S02 and S06.

² Figures are for deaths registered in each calendar year.

³ Deaths of usual residents of Sefton local authority.

⁴ The introduction of 1CD-10 for coding cause of death in 2001 means that data for head injuries in this year and 2002 are not comparable with data for earlier years. The interpretation of international coding rules in ICD-10, compared with the rules used in 1CD-9, has led to an apparent decrease of 40 per cent. in the number deaths coded to head injuries. The figures should therefore be interpreted with caution. The effect of the major changes to mortality statistics in ICD-10 compared with 1CD-9 were described in a report published in May 2002.⁵

⁵ Office for National Statistics. Results of the ICD-10 bridge coding study, England and Wales, 1999. "Health Statistics Quarterly" 14 (2002), 75–83.