In reply: The support for my study1 is pleasing, especially the letter from Martin.

I agree with Hockey and Pitt that including Queensland data would have enhanced my study, as Queensland is the only other Australian State with a substantial injury database like South Australia's and Victoria's. However, when I analysed the Queensland data only around 1% of baby-walker injuries could be classified as "proximity", compared with 20%–25% in Adelaide and Melbourne.

Surveillance collection can very easily miss critical details. The SA questionnaire asks "What was the victim doing at the time of the injury?", then "What went wrong?" and, finally, "How exactly was the injury caused?". As an example, "a child in a baby walker accesses the fireplace and burns her hand". If one or two of the above questions are left out, or the coder does not capture all the detail, this narrative easily becomes "child burns hand on fireplace" and the detail that the baby walker facilitated the child's access to the fireplace is lost.

In 1995, after the Victorian Injury Surveillance System moved to a "minimum" dataset, their "proximity" component dropped to just 1%, the same as for Queensland. Analysts at the Victorian Injury Surveillance System recommended that these post-1995 data not be used for my study. In my opinion the Queensland system has the same systematic problem, and discussions with Hockey suggest that this is a possibility (Richard Hockey, Senior Data Analyst, Queensland Injury Surveillance Unit, personal communication).

My assertion — that the data I used are largely representative of baby walker injury events in metropolitan Australia — is justified, as any variations in "proximity" rates (even if they do exist) caused by different architectural styles in Queensland would represent only a very small proportion of the events Australia-wide.

The presence of additional steps and higher steps would only explain a higher proportion of these types of injuries, and possibly increased severity, but not the almost total absence of "proximity" injuries, as there is no association between them.

The recent finding by the US Consumer Product Safety Commission2 that steps and stairs injuries still occur with new-style walkers confirms the need to discontinue the proposed mandatory regulations and instigate an immediate ban.

The letter from Beard is disturbing in its attitude. Inadequate supervision is another name for victim blaming, and an unsafe environment is a perfect description of a baby walker. Moreover, to suggest that the ban would include any form of purpose-designed apparatus, including a commercial baby walker, to assist disabled children is nonsense.