Volume-outcome relationships in laryngeal trauma processes of care: a retrospective cohort study.

PURPOSE: The extent to which patients with laryngeal trauma undergo investigation and intervention is largely unknown. The objective of this study was to therefore determine the association between hospital volume and processes of care in patients sustaining laryngeal trauma. METHODS: This retrospective cohort study used the American College of Surgeons Trauma Quality Improvement Program database. Adult patients (≥ 18) who sustained traumatic laryngeal injuries between 2012 and 2016 were eligible. The exposure of interest was average annual laryngeal trauma volume categorized into quartiles. The primary and secondary outcomes of interest were the performances of diagnostic and therapeutic laryngeal procedures respectively. Multivariable logistic regression under a generalized estimating equations approach was utilized. RESULTS: In total, 1164 patients were included. The average number of laryngeal trauma cases per hospital ranged from 0.2 to 7.2 per year. Diagnostic procedures were performed in 31% of patients and therapeutic in 19%. In patients with severe laryngeal injuries, diagnostic procedures were performed on a higher proportion of patients at high volume centers than low volume centers (46% vs 25%). In adjusted analysis, volume was not associated with the performance of diagnostic procedures. Patients treated at centers in the second (OR 1.94 [95% CI 1.29-2.90]) and third (OR 1.67 [95% CI 1.08-2.57]) volume quartiles had higher odds of undergoing a therapeutic procedure compared to the lowest volume quartile. CONCLUSION: Hospital volume may be associated with processes of care in laryngeal trauma. Additional research is required to investigate how these findings relate to patient and health system outcomes.