Cumulative Risk Effect on Unintentional Injury for Chinese Rural Children: A Nested case-control study

Abstract Background: Childhood unintentional injuries are the leading cause of death and disability for children. Despite the risk factors that lead to injury occurrence have been identified, the relationship between cumulative risk effect of risk/protection factors on unintentional injuries are unclear. The aim of this study was to explore the cumulative risk effect on unintentional injury of rural children.Methods: We used a nested case-control study design from a cohort database. Cases were children aged 6 to 14 with unintentional injury recorded, including 1,696 children which comprised 424 unintentional injury cases and matched on 1,272 control children. Risk factor index (RFI) and protection factor index (PFI) were used as dependent variables. Binary logistic regressions was used to estimate RFI, PFI and cumulative effect odds ratios (OR) with 95% confidence intervals (CI) for childhood unintentional injury. The linear regression was performed to estimate the effect between RFI, PFI, interactive effect on unintentional injury.Results: The RFI had a significant difference between the two groups (p <0.01). After controlling the significant sociodemographic variables, the risk of unintentional injury increased with the RFI from 1 to 3 (ORRFI(1) = 0.978, 95% CI 0.739-1.296), (ORRFI(2) = 1.720, 95% CI 1.233-2.397), (ORRFI(3) = 5.162, 95% CI 3.129-8.517). While inversely it decreased with PFI increased/increasing. The linear regression indicated RFI, PFI and interactive effect were significant in the regression model, and the interactive effect of RFI⨯ PFI could be used to explain 32.2% the severity of unintentional injury.Conclusions: The cumulative risk effect on unintentional injury could regulate the unintentional injury in childhood. Pediatric care providers should consider a multifactorial interventions especially for the cumulative effect of risk/protection factors for childhood unintentional injury.