Re-triage of severely injured patients in no-fault vs. at-fault states

Abstract

Importance State no-fault laws enforce fewer administrative requirements for automotive insurance to pay hospitals for injury care costs than states without no-fault laws (at-fault states). Objective Determine if no-fault states had lower re-triage (urgent inter-hospital transfer) of patients injured in motor-vehicle collision (MVC) than at-fault states. Design This was an observational retrospective cohort study. Setting FL, NY, MD and WI Healthcare Cost and Utilization Project State Emergency Department and Inpatient Databases from 2016 to 2021. Participants Severely injured [injury severity score (RISS) > 15] Medicare patients. Exposure FL and NY had no-fault laws, while MD and WI were at-fault states. Main outcome Re-triage was defined as same-day inter-hospital transfer to a high-level trauma center. Mixed effects multivariable logistic regression estimated the association between no-fault states and re-triage controlling for age, sex, race, comorbidity, RISS, diagnosis, trauma designation, hospital for-profit, adjusting for clustering within hospitals and states. A moderation analysis with an interaction term for mechanism * fault laws was conducted to estimate whether no-fault laws moderated adjusted odds of re-triage differently among patients severely injured in MVC versus falls. Results In total 6447 Medicare patients in 345 hospitals were severely injured in MVCs among four states. Median age was 70 years [interquartile range (IQR):65–78]. Neurological injury was the most common diagnosis (38.8%). Unadjusted re-triage rates were 2.3% in no-fault and 8.1% in at-fault states (p < 0.001). No-fault states had 0.31 lower adjusted odds of re-triage (95% Confidence Interval:0.17–0.56) of severely patients injured in MVCs compared to at-fault states. A moderation analysis with an interaction term for mechanism * fault laws demonstrated Medicare MVC injured patients in at-fault states had 1.77 higher adjusted odds of re-triage compared to falls in at-fault states (95% Confidence Interval=1.23–2.54). Medicare patients severely injured in MVC in no-fault states had 0.38 adjusted odds of re-triage compared to fall patients in at-fault states, 95% Confidence Interval 0.22–0.66. Conclusion and relevance Automotive insurance laws moderate odds of re-triage among severely injured MVC patients but not fall patients. Level of evidence Level III