OBJECTIVES: In Japan, child restraint use among preschool children started to increase before compulsory child restraint use for children aged 0-5 years was introduced by legislation in April 2000. This study determined the effects of increased child restraint use in reducing motor vehicle occupant injuries among children aged 0-5 years. METHODS: We obtained monthly police data of child vehicle occupant injuries from 1990 to 2009. We calculated monthly ratios of morbidity rates per population of children aged 0-5 years to those of children aged 6-9 years. Time trends of the morbidity rate ratios were analyzed using a joinpoint regression model to determine whether there were trend changes in child occupant injuries and when they occurred if there were trend changes. RESULTS: The morbidity rate ratios showed a slightly increasing trend of 0.03% per month (95% confidence interval [CI], -0.02% to 0.09%) until the change-point in December 1997 (95% CI, July 1996 to January 1999), which then changed to a decreasing trend of -0.14% per month (95% CI, -0.16 to -0.11), with an overall trend change of -0.17% (95% CI, -0.23 to -0.11). No change-point was identified in or around April 2000 when compulsory restraint use was introduced. CONCLUSIONS: The present study used comparative indicators relative to age groups that were not covered by the legislation and showed that a decreasing trend of occupant morbidity among children aged 0-5 years started before the introduction of compulsory restraint use. This change probably reflects the prelegislative voluntary increase in child restraint use.
OBJECTIVES: In Japan, child restraint use among preschool children started to increase before compulsory child restraint use for children aged 0-5 years was introduced by legislation in April 2000. This study determined the effects of increased child restraint use in reducing motor vehicle occupant injuries among children aged 0-5 years. METHODS: We obtained monthly police data of child vehicle occupant injuries from 1990 to 2009. We calculated monthly ratios of morbidity rates per population of children aged 0-5 years to those of children aged 6-9 years. Time trends of the morbidity rate ratios were analyzed using a joinpoint regression model to determine whether there were trend changes in child occupant injuries and when they occurred if there were trend changes. RESULTS: The morbidity rate ratios showed a slightly increasing trend of 0.03% per month (95% confidence interval [CI], -0.02% to 0.09%) until the change-point in December 1997 (95% CI, July 1996 to January 1999), which then changed to a decreasing trend of -0.14% per month (95% CI, -0.16 to -0.11), with an overall trend change of -0.17% (95% CI, -0.23 to -0.11). No change-point was identified in or around April 2000 when compulsory restraint use was introduced. CONCLUSIONS: The present study used comparative indicators relative to age groups that were not covered by the legislation and showed that a decreasing trend of occupant morbidity among children aged 0-5 years started before the introduction of compulsory restraint use. This change probably reflects the prelegislative voluntary increase in child restraint use.
Authors: Huiqian Lei; Jingzhen Yang; Xiangxiang Liu; Xiaojun Chen; Liping Li Journal: Int J Environ Res Public Health Date: 2016-09-28 Impact factor: 3.390