Patient Service Utilization Among Individuals with Co-occurring Disorders: A Comparison of Two Models of Care Coordination.

Healthcare systems have increasingly adopted integrated care models with demonstrated effectiveness. However, few studies examine integrated care for individuals with co-morbid mental illness and medical conditions. This quasi-experimental study compared service use for two integrated care models for patients with co-occurring conditions. We used hierarchical negative binomial and logistic regressions with random effects to test the relationship between integration and service use. Patients treated at co-located agencies had significantly higher odds of inpatient hospitalization compared to those in fully integrated settings. Additionally, some comorbidities had significantly different levels of service use. Patients at co-located agencies had more outpatient and emergency visits, but was not statistically significant. Our findings provide evidence that the model of care may impact service use for patients experiencing co-occurring conditions, however, variations in service use for specific co-morbid conditions highlight the need to examine the specific needs and characteristics of this population.