Risks of organ failures and deaths associated with young-onset dementia after hospitalizations for motor vehicle crash injuries: a nationwide population-based retrospective cohort study

Patients with dementia are at increased risks of adverse consequences associated with motor vehicle crash injury (MVCI). However, studies of the association for patients with young-onset dementia (YOD) are limited. Therefore, we aim to investigate whether YOD was associated with adverse outcomes after hospitalization for MVCI. In this retrospective cohort study, we identified 2052 MVCI patients with YOD (aged 40–64 years) between 2006 and 2015 and included 10 260 matched MVCI patients without YOD (matching ratio: 1:5) from Taiwan’s National Health Insurance Research Database and the Taiwan Police-Reported Traffic Accident Registry. We evaluated the intensive care unit (ICU) admission, organ failure, in-hospital and 30-day mortalities, length of hospital stay, and hospital costs. Compared with participants without dementia, patients with YOD had higher rates of ICU admission (34.31% vs. 20.89%) and respiratory failure (6.04% vs. 2.94%), with a covariate-adjusted odds ratio of 1.50 (95% CI 1.33–1.70) and 1.63 (95% CI 1.24–2.13), respectively. The patients also exhibited higher in-hospital mortality (4.73% vs. 3.12%) and 30-day mortality (5.12% vs. 3.34%) than their non-YOD counterparts, but the risk ratio was not significant after adjusting for transport mode. Moreover, the log means of hospital stay and cost were higher among patients with YOD (0.09 days; 95% CI 0.04–0.14 and NT$0.17; 95% CI 0.11–0.23, respectively). This cohort study determined that YOD may be adversely associated with hospital outcomes among MVCI patients. However, the association between YOD and mortality risk may depend on transport mode.