Website of the Department of Health

Review of disclosure issues

In using and releasing health statistics there is a risk, generally with small numbers, of identifying individuals. To address this, the Department of Health asked - on 9 February 2005 - the National Statistician to provide it with guidelines for interpreting the National Statistics Code of Practice and associated protocols in the handling of health statistics across the health community, in a way that balances data confidentiality risks with the public interest in the use of the figures.

In July 2005, The Office of National Statistics (ONS) published an advisory report on disclosure guidance for abortion statistics. DH Ministers have accepted this advice from the National Statistician.

Annual bulletins, publications and release of abortion statistics for 2003 onwards apply the conclusions of the ONS disclosure review and guidance for abortion statistics.

The guidance provides details on how to identify cells within tabulated statistics where the risks of a breach of confidentiality are unacceptable ("unsafe cells"). It then describes methods for reducing these risks.

For the bulletin, the risks identified have been reduced largely by redesigning tables. However, where table redesign proved to be impossible then suppression was applied to cells with fewer than 5 cases at national level or fewer than 10 cases at sub-national level and for highly sensitive variables such as gestation weeks by medical grounds. The same principles were also applied to tables showing rates and percentages.

• Advisory report on disclosure guidance for abortion statistics, on the ONS website (opens new window)
• Abortion statistics, England and Wales