Reason for withdrawal from publication
This review has been withdrawn from the Cochrane Library because it relies solely on observational data.
The editorial group responsible for this previously published document have withdrawn it from publication.
What's new
| Date | Event | Description |
|---|---|---|
| 9 September 2008 | Amended | Converted to new review format. |
History
Protocol first published: Issue 2, 2001 Review first published: Issue 4, 2003
| Date | Event | Description |
|---|---|---|
| 1 August 2003 | New citation required and conclusions have changed | Substantive amendment |
Sources of support
Internal sources
Department of Public Health, Liverpool University, UK.
External sources
Systematic Reviews Training Unit, Institute of Child Health (UCL), London, UK.
Withdrawn from publication for reasons stated in the review