Influence of alcohol use and other addictive disorders in the costs of emergency department frequent use

Background: A small number of patients make frequent use of the Emergency Department (ED) and account for a disproportionate amount of its total workload and healthcare costs. ED Frequent Users (FU) make 5 or more visits to the ED in a year and often present both medical and social complexity. Addictions and other mental disorders have been described to increase the probability of attending the ED frequently. This study aims to better characterize the role of alcohol use and other addictive disorders in frequent use of a Spanish ED and calculate the impact of this phenomenon in healthcare direct costs.

Methods: Matched case-control study. Cases were adults between 18 and 65 year old that attended 5 or more times the ED of a tertiary hospital in Barcelona between December 2018 and November 2019. Retrospective review of the first electronic register during the study period was used to obtain the study variables (sociodemographic and clinical data) and to compute direct healthcare costs for a single ED visit. Each case was assigned one control of the same age and gender that attended the ED the same date. To compare cases and controls we performed bivariate analyses using McNemar’s test and paired-samples t-test and multivariate analyses using conditional logistic regression. FU with history of alcohol use related problems (AURP) were compared with those FU without AURP: we performed bivariate analyses using independent-samples t-test, one-way ANOVA and Chi square tests; and multivariate analyses using multiple linear regression.

Results: We included 609 pairs, with mean age of 44.57 (Standard Deviation (SD)=13.7) years old. FU presented a mean of 7.35 (SD=1.15) yearly ED attendances. History of alcohol use disorders (AUD) (OR=2.48 (95% CI 1.43-4.30) p= 0.001), addictive (OR=1.45 (95% CI 1.08-1.95) p= 0.013) and psychiatric (OR=2.06 (95% CI 1.51-2.80) p< 0.0005) comorbidities increased the probability of frequently attend the ED. For a single ED visit mean total healthcare direct costs were 44.44 euros (95%CI 13.4-75.5) higher in FU compared to controls (t(608) = 2.811 p=0.005). Among FU, although in bivariate analyses history of AURP, addictive and organic comorbidities seemed to predict higher mean total healthcare costs, in a multiple linear regression only lenght of stay (LoS) (B=0.38 (95%CI 0.363-0.397) p=0.005), Triage level (-19.895 (95%CI (-32.047),(-7.743)) p=0.001) and discharge type of specialty (-10.068 (95%CI (-19.8),( -0.336)) p=0.043) statistically significantly predicted total healthcare costs.

Conclusion: Addictive and other mental health disorders should be assessed in all ED frequent users. Specific protocols to tackle addictive disorders in the ED might not only improve patients’ well-being but also reduce healthcare costs.