Factors Influencing the Frequency of Emergency Department Utilization by Individuals with Substance Use Disorders.

This study assessed the characteristics of individuals with substance use disorders (ISUDs) according to their frequency of emergency department (ED) utilization, and examined which variables were associated with an increase in ED visits using Andersen's model. Data linkage of administrative databanks from three sources [addiction rehabilitation centre registry, physician billing systems, and hospital discharge databank] for 4526 ISUDs was performed. Predisposing, enabling and need factors associated with number of ED visits were determined using a negative binomial regression model and generalised estimating equations. The rate of ED utilization for this population was 9.6 %. Increased number of ED visits was associated with the following variables: older age, social fragmentation, number of consultations with general practitioners, number of consultations with psychiatrists, number of consultations with other types of physicians, alcohol abuse, drug abuse, schizophrenia, anxiety disorders, personality disorders, co-occurring substance dependence and mental disorders, co-occurring substance dependence and chronic physical disorders, and co-occurring mental health disorders and chronic physical disorders. By contrast, a diagnosis of substance dependence, co-occurring drug and alcohol abuse, and a co-occurring diagnosis of substance dependence with mental health and chronic physical disorders decreased ED visits. Efforts to reduce avoidable use of EDs should focus on chronic-disease management and other related strategies aimed at reinforcing services to ISUDs in the community, especially for ISUDs with a co-occurring diagnosis of either mental health disorders or chronic physical disorders.