Relation between increased numbers of safe playing areas and decreased vehicle related child mortality rates in Japan from 1970 to 1985: a trend analysis.

Objectives: To examine vehicle related mortality trends of children in Japan; and to investigate how environmental modifications such as the installation of public parks and pavements are associated with these trends.
Design: Poisson regression was used for trend analysis, and multiple regression modelling was used to investigate the associations between trends in environmental modifications and trends in motor vehicle related child mortality rates.
Setting: Mortality data of Japan from 1970 to 1994, defined as E-code 810-23 from 1970 to 1978 and E810-25 from 1979 to 1994, were obtained from vital statistics. Multiple regression modelling was confined to the 1970-1985 data. Data concerning public parks and other facilities were obtained from the Ministry of Land, Infrastructure, and Transport.
Subjects: Children aged 0-14 years old were examined in this study and divided into two groups: 0-4 and 5-14 years.
Main Results: An increased number of public parks was associated with decreased vehicle related mortality rates among children aged 0-4 years, but not among children aged 5-14. In contrast, there was no association between trends in pavements and mortality rates.
Conclusions: An increased number of public parks might reduce vehicle related preschooler deaths, in particular those involving pedestrians. Safe play areas in residential areas might reduce the risk of vehicle related child death by lessening the journey both to and from such areas as well as reducing the number of children playing on the street. However, such measures might not be effective in reducing the vehicle related mortalities of school age children who have an expanded range of activities and walk longer distances.