Database selection matters: A case study in child restraint use and injury patterns using North Carolina motor...

While proper restraint use is protective against motor traffic vehicle crash (MVTC)-associated morbidity and mortality, it is inconsistently measured across health and MVTC data sources. This project addresses this gap by assessing differences in child restraint measures between two North Carolina (NC) datasets and comparing the utility of these sources to evaluate patterns of child restraint use and associated health outcomes.

We analyzed 2018 NC MVTC and NC Trauma Registry (NCTR) data for children ≤15 years old, both separately and as linked MVTC-NCTR records. We calculated mean and standard deviation for continuous variables and frequency and proportion for categorical variables. Among linked records, we compared reported restraint use and performed age-adjusted logistic regression to estimate associations between restraint use and severe injury.

A lower proportion of pediatric MVTC victims were reported as unrestrained in the MVTC (14.7%) versus NCTR (25.8%) data. Among linked MVTC-NCTR records, only 41.3% featured perfect concordance of restraint information between datasets. Among linked records, child restraint was reported for 31.3% of children, while the NCTR data allowed more granular coding of child restraint (30.3% overall), including child booster seat (13.5%), child car seat (8.7%), infant car seat (4.8%), and unrestrained in child car seat (3.4%). Age-adjusted regression analyses of the linked data revealed that lap/shoulder seatbelt use was significantly associated with lower likelihood of severe injury compared to being unrestrained whether informed by MVTC (OR = 0.39; 95% CI: 0.16, 0.93) or NCTR (OR = 0.38; 95% CI: 0.15, 0.96) data. While the association between reported use of a child car seat and severe injury was not statistically significant in the MVTC data (OR = 0.50; 95% CI: 0.19, 1.32), child car seat use reported in the NCTR data revealed a significant association (OR = 0.16; 95% CI: 0.03, 0.93).

Linked crash and trauma center data allow for identifying important patterns of restraint use among pediatric passengers in MVTCs. Dataset-dependent differences in measuring restraint use have critical public health implications and illustrate the importance of careful dataset selection prior to analysis, as the use of different data sources may impact overall study conclusions.