This pragmatic clinical trial seeks to evaluate the effectiveness of the Consult for Addiction Treatment and Care in Hospitals (CATCH) intervention as a strategy for engaging patients with Opiod Use Disorder (OUD) in addiction treatment.

The overarching objective of our study is to evaluate the effectiveness of CATCH as a strategy for engaging patients with OUD in MAT. A pragmatic trial at 6 hospitals, conducted in collaboration with the New York City Health and Hospitals system (H+H) and the New York City Department of Health and Mental Hygiene (DOHMH), will study the CATCH intervention in real-world settings and at scale. Guided by the RE-AIM evaluation framework, this hybrid effectiveness-implementation study (Type 1) focuses primarily on effectiveness, but also measures implementation outcomes to inform the intervention's adoption and sustainability. A rigorous stepped-wedge cluster randomized trial design determines the impact of CATCH on opioid treatment outcomes in comparison to usual care for a control period, followed by a 12-month intervention period and a maintenance period, and utilizes existing administrative data to evaluate outcomes. Aim 1 (primary aim) is to evaluate the effectiveness of CATCH in increasing post-discharge initiation and engagement in MAT, defined respectively as receiving outpatient MAT within 14 days of discharge, and having at least 2 additional MAT visits in the first month. Aim 2 is to assess the effectiveness of CATCH for increasing treatment retention, defined as continuous receipt of MAT for 6 months. Aim 3 is to compare the frequency of acute care utilization and overdose deaths, and their associated costs, among patients with OUD who are hospitalized during the CATCH period versus usual care. Aim 4 is to evaluate implementation outcomes at CATCH sites using a mixed methods approach to assess the intervention's Reach (proportion of eligible patients reached); Adoption (utilization by medical staff); and Implementation fidelity (barriers to delivering high-quality MAT).

Inclusion Criteria:

• Adult patients (≥18 years);
• Hospitalized for at least 1 night on an inpatient service (not including intensive care);
• Admission or discharge diagnosis (based on ICD-10 codes) of opioid use disorder or opioid poisoning.

Cases are excluded if they received MAT (buprenorphine, methadone maintenance treatment, or naltrexone) in the 30 days prior to admission. Cases included in the intervention condition must have been admitted on a date following implementation of CATCH.

Exclusion Criteria:

• Lack of fluency in English, unable to provide informed consent.

Our study retrospectively analyzes administrative data for patients with OUD who have been hospitalized at the participating sites. These patients are not recruited or enrolled.The cases identified through administrative data consists of individuals with OUD who are hospitalized at one of the six study sites. We anticipate that the characteristics of this population will vary by site, given the differences in patient populations served by each of the participating hospitals. Overall, we expect that cases will have the following demographic characteristics: 28% female; 14% Hispanic; 24% Black, 37% White, 1% Asian, 38% mixed race/other; 4% age 18-25, 33% age 26-45, 55% age 46-65, 7% >65 years.

The individual patient data collected for this study will not be made available to others, as data has been extracted from New York State Medicaid claims, which is highly confidential. The data use agreement which allows the study team access to this data does not permit sharing with individuals unless they are approved by New York State.