A Cohort Study Evaluating the Association Between Concurrent Mental Disorders, Mortality, Morbidity, and Continuous Treatment Retention for Patients in Opioid Agonist Treatment (OAT) Across Ontario, Canada Using Administrative Health Data

Abstract

<jats:title>Abstract</jats:title> <jats:p>Background: Due to the high prevalence of mental disorders among people with opioid use disorder, the objective of this study was to determine the association between concurrent mental disorders, mortality, morbidity and continuous treatment retention for patients in opioid agonist treatment in Ontario, Canada. Methods: We conducted a retrospective cohort study of patients enrolled in opioid agonist treatment between January 1, 2011, and December 31, 2015. Patients were stratified into two groups: those diagnosed with concurrent mental disorders and opioid use disorder and those with opioid use disorder only, using data from the Ontario Health Insurance Plan Database, Ontario Drug Benefit Plan Database. The primary outcome studied was all-cause mortality using data from the Registered Persons Database. Emergency Department visits from the National Ambulatory Care Database, hospitalizations Discharge Abstract Database, and continuous retention in treatment, defined as one year of uninterrupted opioid agonist treatment using data from the Ontario Drug Benefit Plan Database, were measured as secondary outcomes. Encrypted patient identifiers were used to link information across databases.Results: We identified 55,924 individuals enrolled in opioid agonist treatment, and 87% had a concurrent mental disorder diagnosis during this period. We observed that having a mental disorder was associated with an increased likelihood of all-cause mortality (Odds Ratio (OR) 1.4; 95% Confidence Interval (CI) 1.2-1.5. For patients diagnosed with mental disorders the estimated rate of ED visits per year was 2.25 times higher and estimated rate of hospitalization per year 1.67 times higher than for patients with no mental disorders. However, there was no association between having a diagnosis of a mental disorder and one-year treatment retention in OAT adjusted Hazard Ratio (HR) = 1.0; 95%CI 0.9 to 1.1).Conclusion: Our findings highlight the consequences of the high prevalence of mental disorders for individuals with opioid use disorder in Ontario, Canada</jats:p>

Community trial evaluating the integration of Indigenous healing practices and a harm reduction approach with principles of seeking safety in an Indigenous residential treatment program in northern Ontario

“…It is important to mention that the rates of health service use were consistently lower in this study population compared to rates shown in other studies in similar cohorts [42]. For instance, the mean ED visits in this study were approximately 1.5 visits in 6 months compared to a recent cohort study on people with opioid use disorder in Fig.…”

“…Baseline covariates including age, sex, self-identified Indigenous, Indigenous status, living on-reserve, living in rural or northern areas, primary substance use, income quintile, and opioid agonist treatment (OAT) participation before attending Benbowopka Treatment Program were used to describe patients pre and post-IHSS implementation and used as adjust for potential confounding. The variables were chosen based on factors that are known to influence treatment retention, and health services use from the literature [40][41][42][43].…”

Untangling the Complexities of Substance Use Initiation and Recovery: Client Reflections on Opioid Use Prevention and Recovery From a Social-Ecological Perspective

“…26-29 Limited access to mental health and other addiction services for concurrent conditions is associated with adverse treatment outcomes. 30 Moreover, social determinants of health, such as income, employment, childhood experiences, social support, and physical environments, significantly affect the risk of developing OUD in Indigenous clients and their ability to access care. 31…”

Evaluating the effectiveness of concurrent opioid agonist treatment and physician-based mental health services for patients with mental disorders in Ontario, Canada

“…Importantly, it is estimated that 50-90% of those who develop OUD are also diagnosed with a concurrent mental disorder [10]. The most prevalent mental disorders reported in this population are anxiety and mood disorders, including major depression and bipolar disorder [11,12]. It is essential to highlight the potential underestimation of the prevalence of post-traumatic stress disorder (PTSD) since it is known to be often misdiagnosed as another anxiety, depression or other related disorders [13][14][15][16].…”

“…Although OAT has been shown to be very effective, its efficacy may be negatively impacted by concurrent issues, including mental disorders [11,12], psychosocial problems [10-12, 17, 27] and infections such as HIV and viral Hepatitis [28][29][30][31][32]. The prevalence of comorbidities present major public health concerns in terms of the risk of complications from chronic physical health issues as well as poorer health system and treatment outcomes [11,17,33,34]. As the severity of the opioid issue continues to rise, the expansion and integration of OAT with other health services-more specifically, primary care and mental health services-has been recommended as a strategy to mitigate the opioid crisis [35,36].…”