Novel Application of a Multistate Model to Evaluate the Opioid Use Disorder Care Cascade: A Retrospective Cohort Study

Background Evaluating the opioid use disorder (OUD) care cascade can improve OUD treatment retention and care. Objectives To identify risk and protective factors for retention among patients in OUD treatment. Methods We conducted a retrospective cohort study among patients diagnosed with OUD using data from the Rhode Island (RI) All-Payer Claims Database from 2011 to 2019. Patients who initiated treatment (Stage 2) were classified into sub-stages of retention (Stage 3) corresponding to multistate modeling states capturing early retention (sub-stage 1), short and long-term retention (sub-stage 2), and short and long-term disengagement (sub-stage 3). The association of baseline characteristics with state transitions were evaluated. Results A cohort of 6,939 RI residents diagnosed with OUD included 41% aged 40 to 60 years, 57.6% male, and 70.8% Medicaid beneficiaries. In sub-stage 1, cannabis (Relative risk ratios (RRR) = 1.16; 95% confidence interval (CI) = 1.04,1.29) and cocaine use disorders (RRR=1.15; 95% CI=1.05,1.25) increased early disengagement risk after engagement. Medicaid beneficiaries were less likely to experience early disengagement (RRR=0.81; 95% CI =0.76,0.87). In sub-stage 2, alcohol (RRR=1.29; 95% CI=1.13,1.47) or cocaine use disorders (RRR=1.18; 95% CI=1.01,1.40) increased risk of disengagement among patients in the retention states. In sub-stage 3, tobacco (RRR=1.10; 95% CI=1.01,1.21) and alcohol (RRR=1.14; 95% CI=1.03,1.27) use disorders were associated with re-engagement from disengaged states. Conclusion The multistate model applied to a cohort of patients initiating medication for OUD led to the identification of factors associated with treatment engagement and retention. These results may guide strategies to sustain treatment among OUD patients. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The project described was supported by Award Number 1DP2DA046856-01 from the National Institute on Drug Abuse of the National Institutes of Health, Institutional Development Award Number U54GM115677 and P20-GM125507 from the National Institute of General Medical Sciences of the National Institutes of Health (NIGMS). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee/IRB of Brown University gave ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to Brown University.