Scooting mishaps

We were pleased to see Erica Weir's article on injuries associated with scooters.1 It is good to inform readers of the causes of injuries, how they can be prevented and where further information can be obtained.

The Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) is an emergency department-based injury surveillance program and is a good source of information on the circumstances in which injuries occur. However, the CHIRPP data are not population based and cannot be used to calculate injury rates.

In the CHIRPP report on scooter injuries, Weir has unfortunately misinterpreted information from the first table as rate of injuries per 100 000 people. The number of cases per 100 000 is actually the number of scooter injuries per 100 000 reported injuries of all kinds for people in each age group. This calculation is done to compensate for (1) the skewed age distribution of the CHIRPP data that results from collecting data in 10 pediatric and 5 general hospitals and (2) the use of age groupings of unequal range. It is therefore possible to identify the age group or groups in which the relevant injury has the highest relative frequency. In this case, the relative frequency of scooter injuries was highest among children aged 8–13, accounting for about 72 out of every 100 000 injuries in the CHIRPP database.

Susan G. Mackenzie Senior Epidemiologist, Injury Section Health Surveillance and Epidemiology Division Health Canada Ottawa, Ont.