(174) Intensive Community Care Reduces Over-Utilization of Healthcare Resources

Background & Introduction: High-frequency acute care utilization and poor engagement with outpatient services among individuals with substance use disorders (SUD) remains a persistent challenge, often reflecting unmet needs in both addiction and general medical care.1-2 Preliminary evidence suggests that intensive, longitudinal community care improves treatment engagement, housing stability, and retention in care for individuals with severe SUD or co-occurring psychiatric disorders and reduces illicit drug use, while effect on emergency department visits and inpatient time is less studied.3-4 Modest sample sizes with substantial heterogeneity in intervention components, patient populations, and outcome measures across studies make it difficult to determine how psychosocial services should best be implemented.5
The Access Transformative Outreach Program (ATOP) serves patients in Denver with severe SUD through multidisciplinary, intensive community-based care. Eligible individuals are patients >18 years old with >6 presentations within a 60-day period across emergency departments, inpatient units, or Denver CARES (3.2 withdrawal management facility associated with Denver Health). All individuals must also have a severe SUD and cannot be currently engaged in assertive community treatment (ACT) or high-intensity treatment team (HITT) elsewhere. We seek to further assess the impact of intensive community care on this population by evaluating patient utilization patterns.

Methods: Data were extracted from Denver Health’s Epic electronic health record (EHR), with a date range of August 1, 2022 (program inception) to July 31, 2025. The analysis included adults enrolled in the ATOP program who completed intake and were active during the study period, as well as previously enrolled patients deceased or discharged in good standing. Patients were required to have sufficient follow-up time for inclusion in one of five post-intake experimental periods (6–30 months). For this poster, all experimental periods were compared with a single pre-intake control period consisting of the same patients during the 6 months prior to ATOP enrollment, enabling paired analyses. Outcomes included healthcare utilization, diagnoses defined by ICD-10 groupings, and housing status derived from multiple EHR sources. Due to small sample size and non-normal distributions, paired comparisons were conducted using two-tailed Wilcoxon signed-rank tests, with zero-difference pairs excluded. To address multiple comparisons across outcomes and timeframes, Benjamini–Hochberg false discovery rate (FDR) adjustments were applied.

Results: ATOP patients (n=49) were identified for this study. Patients were mostly male (79.6%), white (40.8%) or hispanic (40.8%), aged 46-64 (51%), and receiving Medicaid (85.7%). Lifetime SUD diagnoses among participants included alcohol use disorder (100%), stimulant use disorder (71.4%), opioid use disorder (51%), and benzodiazepine use disorder (10.2%). Participants also had psychiatric diagnoses of anxiety disorder (75.5%), depressive disorder (63.3%), post-traumatic stress disorder (51.0%), psychosis (34.7%), and/or bipolar disorder (22.5%). 70% of ATOP patients had been unhoused at some time throughout their life.
ATOP patients (n=40) were compared to themselves 6 months prior to participation in ATOP using two-tailed Wilcoxon Signed-Rank Tests. Nine patients were excluded from analysis because they had not been in the program for at least 6 months. ATOP appointments were excluded from visit counts. Results showed that after enrollment in ATOP (0-6 months) there was a statistically significant increase in average monthly outpatient primary care and specialist appointment attendance (1.39 vs 2.52; p< 0.01) and outpatient psychiatry visits (0.42 vs 1.21; p< 0.01). This improvement continued to show statistical significance up to 2 years (1.39 vs 3.28; p< 0.01) and 2.5 years (1.39 vs 2.61; p=0.034) after ATOP enrollment.
After 6-12 months of participation in ATOP there was a statistically significant reduction in average monthly emergency room presentations (1.38 vs. 0.95; p=0.039). After 2.5 years, presentations to emergency rooms continued to be reduced (1.38 vs 0.69; p=0.042). There was also a significant reduction in presentations to combined psychiatric emergency services and 3.2 withdrawal management services (0.99 vs 0.52; p< 0.01) after 6-12 months of engagement with ATOP. There continued to be a statistically significant reduction in these presentations observed up to 2 years after enrollment in ATOP.

Conclusion & Discussion: Patient engagement with ATOP has resulted in a significant increase in outpatient primary care and mental health visits in a population of patients with historically poor outpatient follow up. Additionally, patients enrolled in ATOP have demonstrated a significant decrease in utilization of emergency room services and 3.2 withdrawal management. These changes have continued to persist up to 2.5 years after initial enrollment in ATOP. This reduction in utilization of services may lead to a reduction in cost burden on hospital systems in addition to improving patient outcomes. These results suggest positive impacts of intensive community care on healthcare engagement for individuals with substance use disorders. A limitation of this study was that participants were mostly male. Given the small sample size, the study may not be sufficiently powered to detect some changes in utilization. Additionally, as the ATOP program is relatively new there is limited data regarding utilization patterns for patients more than 3 years after ATOP intake or after graduating from ATOP.

References: 1. Substance Abuse and Mental Health Services Administration: Treatment Episode Data Set (TEDS) 2023: Admissions to and Discharges from Substance Use Treatment Services Reported by Single State Agencies. Publication No. PEP25-07-014, Substance Abuse and Mental Health Services Administration, 2025

2. Lewer D, Freer J, King E, et al. Frequency of health-care utilization by adults who use illicit drugs: a systematic review and meta-analysis. Addiction. 2020;115(6):1011-1023. doi:10.1111/add.14892

3. Vogel EA, Ly K, Ramo DE, Satterfield J. Strategies to improve treatment utilization for substance use disorders: A systematic review of intervention studies. Drug Alcohol Depend. 2020;212:108065. doi:10.1016/j.drugalcdep.2020.108065

4. Helm AF, Andre MA, Shaffer PM, et al. Multicomponent Co-Occurring Disorders Treatment and Wraparound Services for Individuals Experiencing Chronic Homelessness. Community Ment Health J. 2024;60(6):1203-1213. doi:10.1007/s10597-024-01271-w

5. Hunt GE, Siegfried N, Morley K, Brooke-Sumner C, Cleary M. Psychosocial interventions for people with both severe mental illness and substance misuse. Cochrane Database Syst Rev. 2019;12(12):CD001088. Published 2019 Dec 12. doi:10.1002/14651858.CD001088.pub4