"We wish we had the option": a qualitative study of women's perspectives and experiences with contraception in a provincial prison in Ontario, Canada.

BACKGROUND: Evidence suggests that women who are incarcerated desire access to contraception while incarcerated, and that this need is not currently being met. Our objective in this study was to explore the perspectives and experiences of women in prisons regarding contraception and contraception access using data from focus groups with women in a provincial prison. We analyzed focus group data collected in a provincial prison in Ontario, Canada using content analysis and a constructivist epistemology. RESULTS: We conducted three focus groups, each approximately one hour in length. Discussions revolved around (1) knowledge and decision making about contraception, (2) accessing contraception, and (3) ideas for increasing access to contraception in the prison setting. Decision making about contraception was mainly related to concerns about side effects, consistent access to care, impacts on future fertility, and autonomy around decision-making. Participants discussed a wide range of experiences with contraception. Ideas for increasing access to contraception included information sessions, inclusion of discussions about contraception as a component of admission and release planning, and time spent in prison as a crucial juncture for decision-making about contraception. CONCLUSIONS: More qualitative research is needed to better understand the needs of women in prisons related to contraception. The findings of this study suggest that programs should focus on consistency and continuity of access to care, education opportunities, and integration of discussions about contraception into official admission and release procedures.

Accidental substance-related acute toxicity deaths among youth in Canada: a descriptive analysis of a national chart review study of coroner and medical examiner data. / Décès accidentels attribuables à une intoxication aiguë due à une substance chez les jeunes au Canada : analyse descriptive d'une étude nationale portant sur l'examen des dossiers des données de coroners et de médecins légistes.

INTRODUCTION: Substance-related acute toxicity deaths (ATDs) are a public health crisis in Canada. Youth are often at higher risk for substance use due to social, environmental and structural factors. The objectives of this study were to understand the characteristics of youth (aged 12-24 years) dying of accidental acute toxicity in Canada and examine the substances contributing to and circumstances surrounding youth ATDs. METHODS: Data from a national chart review study of coroner and medical examiner data on ATDs that occurred in Canada between 2016 and 2017 were used to conduct descriptive analyses with proportions, mortality rates and proportionate mortality rates. Where possible, youth in the chart review study were compared with youth in the general population and youth who died of all causes, using census data. RESULTS: Of the 732 youth who died of accidental acute toxicity in 2016-2017, most (94%) were aged 18 to 24 years. Youth aged 20 to 24 who were unemployed, unhoused or living in collective housing were overrepresented among accidental ATDs. Many of the youth aged 12 to 24 who died of accidental acute toxicity had a documented history of substance use. Fentanyl, cocaine and methamphetamine were the most common substances contributing to death, and 38% of the deaths were witnessed or potentially witnessed. CONCLUSION: The findings of this study point to the need for early prevention and harm reduction strategies and programs that address mental health, exposure to trauma, unemployment and housing instability to reduce the harms of substance use on Canadian youth.

Intellectual and developmental disabilities in Ontario's criminal justice and forensic mental health systems: Using data to tell the story.

BACKGROUND: International studies show that adults with intellectual and developmental disabilities (IDD) are disproportionately represented in the criminal justice and forensic mental health systems; however, it is difficult to capture their involvement across systems in any one jurisdiction. AIMS: The current study aimed to estimate the prevalence of IDD across different parts of the criminal justice and forensic mental health systems in Ontario and to describe the demographic and clinical profiles of these individuals relative to their counterparts without IDD. METHODS: This project utilised administrative data to identify and describe the demographic and clinical characteristics of adults with IDD and criminal justice or forensic involvement across four sectors: federal correctional facilities, provincial correctional facilities, forensic inpatient mental health care and community mental health programmes. Questions were driven by and results were contextualised by a project advisory group and people with lived experience from the different sectors studied, resulting in a series of recommendations. RESULTS: Adults with IDD were over-represented in each of the four settings, ranging from 2.1% in federal corrections to 16.7% in forensic inpatient care. Between 20% (forensic inpatient) and 38.4% (provincial corrections) were under the age of 25 and between 34.5% (forensic inpatient) and 41.8% (provincial corrections) resided in the lowest income neighbourhoods. Medical complexity and rates of co-occurring mental health conditions were higher for people with IDD than those without IDD in federal and provincial corrections. CONCLUSIONS: Establishing a population-based understanding of people with IDD within these sectors is an essential first step towards understanding and addressing service and care needs. Building on the perspectives of people who work in and use these systems, this paper concludes with intervention recommendations before, during and after justice involvement.

Chronic Psychotic Disorders and Correctional Involvement: A Population-Based Matched Case-Control Study in Ontario, Canada.

OBJECTIVE: Individuals with chronic psychotic disorders are overrepresented in correctional facilities, but little is known about factors that increase the risk of correctional involvement. The objective of this study was to compare individuals with chronic psychotic disorders who were released from correctional facilities in Ontario to individuals with chronic psychotic disorders but no correctional involvement on sociodemographic, clinical, and prior mental health-related health service utilization characteristics. METHOD: All individuals with chronic psychotic disorders who were released from a provincial correctional facility in Ontario in 2010 were matched (1:2) by age and sex to Ontario residents with chronic psychotic disorders and no correctional involvement. Covariates included sociodemographic (rural residence, marginalization such as residential instability quintile, material deprivation quintile, dependency quintile, and ethnic concentration quintile) and clinical (duration of chronic psychotic disorder and comorbidities) characteristics, and mental health-related health service utilization characteristics (primary care physician, psychiatrist and emergency department visits, and hospitalizations) 1 and 3 years prior to correctional involvement. The association between correctional involvement and prior health service utilization was measured by estimating incidence rate ratios using Poisson and negative-binomial regressions. RESULTS: Individuals with correctional involvement (N = 3,197) lived in neighbourhoods with higher material deprivation and residential instability, and had a shorter duration of illness, and more psychosocial comorbidities (e.g., behavioural issues and depression) than individuals without correctional involvement (N = 6,393). Adjusting for sociodemographic and clinical variables, individuals with correctional involvement had a higher rate of mental health-related primary care physician visits, emergency department visits, and hospitalizations but a lower rate of psychiatrist visits prior to correctional involvement, compared to individuals without correctional involvement. CONCLUSIONS: Despite higher mental health-related comorbidities and higher rates of accessing acute mental health services among individuals with chronic psychotic disorders and correctional involvement, visits to psychiatrists prior to involvement were low.

The Association Between Prior Mental Health Service Utilization and Risk of Recidivism among Incarcerated Ontario Residents.

BACKGROUND: There is mixed evidence on the link between mental health and addiction (MHA) history and recidivism. Few studies have examined post-release MHA care. Our objective was to examine the association between prior (pre-incarceration) MHA service use and post-release recidivism and service use. METHODS: We conducted a population-based cohort study linking individuals held in provincial correctional institutions in 2010 to health administrative databases. Prior MHA service use was assigned hierarchically in order of hospitalization, emergency department visit and outpatient visit. We followed up individuals post-release for up to 5 years for the first occurrence of recidivism and MHA hospitalization, emergency department visit and outpatient visit. We use Cox-proportional hazards models to examine the association between prior MHA service use and each outcome adjusting for prior correctional involvement and demographic characteristics. RESULTS: Among a sample consisting of 45,890 individuals, we found that prior MHA service use was moderately associated with recidivism (hazard ratio (HR): 1.20-1.50, all P < 0.001), with secondary analyses finding larger associations for addiction service use (HR range: 1.34-1.54, all P < 0.001) than for mental health service use (HR range: 1.09-1.18, all P < 0.001). We found high levels of post-release MHA hospitalization and low levels of outpatient MHA care relative to need even among individuals with prior MHA hospitalization. DISCUSSION: Despite a high risk of recidivism and acute MHA utilization post-release, we found low access to MHA outpatient care, highlighting the necessity for greater efforts to facilitate access to care and care integration for individuals with mental health needs in correctional facilities.

Opioid toxicity deaths in Black persons who experienced provincial incarceration in Ontario, Canada 2015-2020: A population-based study.

OBJECTIVE: In the context of mass incarceration and the opioid toxicity crisis in North America, there is a lack of data on the burden of opioid toxicity deaths in Black persons who experience incarceration. We aimed to describe absolute and relative opioid toxicity mortality for Black persons who experienced incarceration in Ontario, Canada between 2015 and 2020. METHODS: We linked data for all persons incarcerated in provincial correctional facilities and all persons who died from opioid toxicity in Ontario between 2015 and 2020, and accessed public data on population sizes. We described the characteristics of Black persons who were incarcerated and died from opioid toxicity, and calculated absolute mortality rates, as well as age-standardized mortality rates compared with all persons in Ontario not incarcerated during this period. RESULTS: Between 2015 and 2020, 0.9% (n = 137) of 16,177 Black persons who experienced incarceration died from opioid toxicity in custody or post-release, for an opioid toxicity death rate of 0.207 per 100 person years. In the two weeks post-release, the opioid toxicity death rate was 1.34 per 100 person years. Standardized for age and compared with persons not incarcerated, the mortality ratio (SMR) was 17.8 (95%CI 16.4-23.1) for Black persons who experienced incarceration. CONCLUSIONS: We identified a large, inequitable burden of opioid toxicity death for Black persons who experience incarceration in Ontario, Canada. Work is needed to support access to culturally appropriate prevention and treatment in custody and post-release for persons who are Black, and to prevent incarceration and improve determinants of health.

The impact of COVID-19 on opioid toxicity deaths for people who experience incarceration compared to the general population in Ontario: A whole population data linkage study.

BACKGROUND: To inform preparedness and population health action, we need to understand the effects of COVID-19 on health inequities. In this study, we assess the impact of COVID-19 on opioid toxicity deaths among people who experience incarceration compared to others in the general population in Ontario, Canada. METHODS: We conducted a retrospective cohort study for the period of January 1, 2015 to December 31, 2020. We accessed and linked coronial data on all opioid toxicity deaths in Ontario with correctional data for people aged 18 years and older who were incarcerated in a provincial correctional facility. We used data from the Statistics Canada Census to calculate whole population rates. We used an interrupted time series design and segmented regression to assess for change in the level or rate of increase in deaths due to opioid toxicity coinciding with the COVID-19 pandemic. We compared the impact of COVID-19 on the opioid toxicity death rates for people exposed and not exposed to incarceration. RESULTS: Rates of opioid toxicity death increased with a linear positive slope in both persons exposed to incarceration and those not exposed over the study period. The start of COVID-19 measures coincided with a marked upward shift in the trend lines with modification of the effect of COVID-19 by both sex and exposure to incarceration. For persons exposed to incarceration, the risk ratio (RR) was 1.50 (95%CI 1.35-1.69) for males and 1.21 (95%CI 1.06-1.42) for females, and for persons not exposed to incarceration, the RR was 1.25 (95%CI 1.13-1.38) for males and not significant for females. CONCLUSIONS: COVID-19 substantially exacerbated the risk of opioid toxicity death, impacting males and females who experienced incarceration more than those who had not, with an immediate stepwise increase in risk but no change in the rate of increase of risk over time. Public health work, including pandemic preparedness, should consider the specific needs and circumstances of people who experience incarceration.

Burden of opioid toxicity death in the fentanyl-dominant era for people who experience incarceration in Ontario, Canada, 2015-2020: a whole population retrospective cohort study.

OBJECTIVES: To describe mortality due to opioid toxicity among people who experienced incarceration in Ontario between 2015 and 2020, during the fentanyl-dominant era. DESIGN: In this retrospective cohort study, we linked Ontario coronial data on opioid toxicity deaths between 2015 and 2020 with correctional data for adults incarcerated in Ontario provincial correctional facilities. SETTING: Ontario, Canada. PARTICIPANTS: Whole population data. MAIN OUTCOMES AND MEASURES: The primary outcome was opioid toxicity death and the exposure was any incarceration in a provincial correctional facility between 2015 and 2020. We calculated crude death rates and age-standardised mortality ratios (SMR). RESULTS: Between 2015 and 2020, 8460 people died from opioid toxicity in Ontario. Of those, 2207 (26.1%) were exposed to incarceration during the study period. Among those exposed to incarceration during the study period (n=1 29 152), 1.7% died from opioid toxicity during this period. Crude opioid toxicity death rates per 10 000 persons years were 43.6 (95% CI=41.8 to 45.5) for those exposed to incarceration and 0.95 (95% CI=0.93 to 0.97) for those not exposed. Compared with those not exposed, the SMR for people exposed to incarceration was 31.2 (95% CI=29.8 to 32.6), and differed by sex, at 28.1 (95% CI=26.7 to 29.5) for males and 77.7 (95% CI=69.6 to 85.9) for females. For those exposed to incarceration who died from opioid toxicity, 10.6% died within 14 days of release and the risk was highest between days 4 and 7 postrelease, at 288.1 per 10 000 person years (95% CI=227.8 to 348.1). CONCLUSIONS: The risk of opioid toxicity death is many times higher for people who experience incarceration compared with others in Ontario. Risk is markedly elevated in the week after release, and women who experience incarceration have a substantially higher SMR than men who experience incarceration. Initiatives to prevent deaths should consider programmes and policies in correctional facilities to address high risk on release.

Cancer equity for those impacted by mass incarceration.

The cancer disparities between people with incarceration histories compared with those who do not have those histories are vast. Opportunities for bolstering cancer equity among those impacted by mass incarceration exist in criminal legal system policy; carceral, community, and public health linkages; better cancer prevention, screening, and treatment services in carceral settings; expansion of health insurance; education of professionals; and use of carceral sites for health promotion and transition to community care. Clinicians, researchers, persons with a history of incarceration, carceral administrators, policy makers, and community advocates could play a cancer equity role in each of these areas. Raising awareness and setting a cancer equity plan of action are critical to reducing cancer disparities among those affected by mass incarceration.

Opioid agonist treatment take-home doses ('carries'): Are current guidelines resulting in low treatment coverage among high-risk populations in Canada and the USA?

Opioid agonist treatment (OAT) is the primary intervention for opioid use disorder (OUD) in Canada and the USA. Yet, a number of barriers contribute to sub-optimal treatment uptake and retention, including daily-supervised medication administration. Thus, clients are eventually granted access to take-home OAT doses (i.e., 'carries') to reduce this burden. However, this decision is based on physician discretion and whether patients can demonstrate stability in various life domains, many of which are inextricably linked to the social determinants of health (SDOH). Current Canadian and USA OAT carry guidance documents are not standardized and do not take the SDOH into consideration, resulting in the potential for inequitable access to OAT carries, which may be the case particularly among marginalized populations such as individuals with OUD who have been released from custody. This perspective article posits that current OAT guidelines contribute to inequities in access to OAT carries, and that these inequities likely result in disproportionately low coverage for OUD treatment among some high-risk groups, including individuals on release from incarceration in particular. Relevant impacts of COVID-19 and related policy changes are considered, and suggestions and recommendations to amend current OAT guidance documents are provided.

Lived experiences of pregnancy and prison through a reproductive justice lens: A qualitative meta-synthesis.

As rates with which women are incarcerated have risen around the world, research examining how incarceration affects the health of people who are pregnant, their newborns, and their family members has burgeoned. Lived experience is seldom accounted for in this research, however, highlighting a gap with relevance to advocates, policy makers, researchers, and practitioners seeking to better understand health inequities and redress human suffering. In this paper we present a qualitative meta-synthesis of 31 papers reporting qualitative studies of how people who are incarcerated in prisons and jails around the world experience pregnancy, labour and childbirth, and the postpartum period. Theoretical perspectives from the reproductive justice and prison abolition movements guided our analysis, which identified connectedness (to baby) and disconnectedness (from support) as twinned themes characterizing the lived experiences of navigating pregnancy in a carceral institution. We argue that the conditions of reproductive justice - including self-determination in pregnancy, in parenting, and in managing one's reproductive capacity - are fundamentally irreconcilable with mass incarceration. We conclude by considering the strategic opportunities for health practitioners and researchers to support the movement for prison abolition by mobilizing health-focused arguments for decarceration.

The health impacts of the COVID-19 pandemic on adults who experience imprisonment globally: A mixed methods systematic review.

BACKGROUND: The prison setting and health status of people who experience imprisonment increase the risks of COVID-19 infection and sequelae, and other health impacts of the COVID-19 pandemic. OBJECTIVES: To conduct a mixed methods systematic review on the impacts of the COVID-19 pandemic on the health of people who experience imprisonment. DATA SOURCES: We searched Medline, PsycINFO, Embase, the Cochrane Library, Social Sciences Abstracts, CINAHL, Applied Social Sciences Index and Abstracts, Sociological Abstracts, Sociology Database, Coronavirus Research Database, ERIC, Proquest Dissertations and Theses, Web of Science, and Scopus in October 2021. We reviewed reference lists for included studies. STUDY ELIGIBILITY CRITERIA: Original research conducted in or after December 2019 on health impacts of the COVID-19 pandemic on adults in prisons or within three months of release. STUDY APPRAISAL AND SYNTHESIS METHODS: We used the Joanna Briggs Institute's Critical Appraisal Checklist for Qualitative Research for qualitative studies and the Joanna Briggs Institute's Critical Appraisal Checklist for Studies Reporting Prevalence Data for quantitative studies. We qualitized quantitative data and extracted qualitative data, coded data, and collated similar data into categories. RESULTS: We identified 62 studies. People in prisons had disproportionately high rates of COVID-19 infection and COVID-19 mortality. During the pandemic, all-cause mortality worsened, access to health care and other services worsened, and there were major impacts on mental wellbeing and on relationships with family and staff. There was limited evidence regarding key primary and secondary prevention strategies. LIMITATIONS: Our search was limited to databases. As the COVID-19 pandemic is ongoing, more evidence will emerge. CONCLUSIONS: Prisons and people who experience imprisonment should be prioritized for COVID-19 response and recovery efforts, and an explicit focus on prisons is needed for ongoing public health work including emergency preparedness. PROSPERO REGISTRATION NUMBER: 239324.

Rising syphilis rates in Canada, 2011-2020.

Background: Syphilis rates are of public health concern in Canada, with multiple jurisdictions reporting outbreaks over the past five years. The objective of this article is to describe trends in infectious and congenital syphilis in Canada 2011-2020. Methods: Routine surveillance of syphilis is conducted through the Canadian Notifiable Disease Surveillance System (CNDSS). In response to rising rates of syphilis, all provinces and territories (P/Ts) have also submitted enhanced surveillance data on infectious syphilis to the Public Health Agency of Canada through the Syphilis Outbreak Investigation Coordinating Committee (SOICC) starting in 2018. Descriptive analyses of CNDSS and SOICC surveillance data 2011-2020 by age, sex, pregnancy status, male sexual orientation and P/Ts were performed. Results: The national rate of infectious syphilis increased from 5.1 per 100,000 population in 2011 to 24.7 per 100,000 population in 2020.The rates increased in almost all P/Ts, with the Prairie provinces reporting the greatest relative increases from 2016 to 2020 (more than 400%). Rates in males were consistently higher than rates in females over the past 10 years; however, from 2016 to 2020, rates among females increased by 773%, compared with 73% among males. Although the proportion of cases who self-identify as gay, bisexual and other men who have sex with men decreased from 54% to 38% between 2018 and 2020, they still represent a high proportion of cases (according to data from eight P/Ts). From 2016 to 2020, rates of infectious syphilis increased in every age group, especially in females aged 15-39 years. Confirmed early congenital syphilis cases for 2020 increased considerably from prior years, with 50 cases reported in 2020, compared with 4 cases in 2016. Conclusion: Infectious and congenital syphilis rates are a growing concern in Canada and the nature of the syphilis epidemics across Canada appears to be evolving, as evidenced by recent trends. More data and research are needed to better understand the drivers associated with the recent changes in the epidemiology of syphilis in Canada.

Intellectual/developmental disabilities among people incarcerated in federal correctional facilities in Ontario, Canada: Examining prevalence, health and correctional characteristics.

BACKGROUND: There is little research with people who experience intellectual/developmental disabilities and imprisonment. METHODS: The study linked health and correctional data to examine prevalence of intellectual/developmental disabilities and health and correctional characteristics among adults experiencing their first federal incarceration between 1 January 2002 and 31 December 2011 (n = 9278) and two non-incarcerated groups (n = 10,086,802). RESULTS: The prevalence of intellectual/developmental disabilities was 2.1% in the incarcerated group and 0.9% in the non-incarcerated group. Before incarceration, those with, versus without, intellectual/developmental disabilities were at greater risk of traumatic brain injury, mental illness, and substance use disorders. While incarcerated, those with intellectual/developmental disabilities were more likely to incur serious institutional disciplinary charges. Post-incarceration, persons with intellectual/developmental disabilities were at greater risk of emergency department visits, and psychiatric and acute hospitalizations, than the non-incarcerated groups. CONCLUSIONS: People with intellectual/developmental disabilities are overrepresented in Canadian federal correctional institutions. The authors offer strategies to support people prior to, during, and post-incarceration.

Buprenorphine/naloxone access for people with opioid use disorder in correctional facilities: taking steps to support knowledge translation.

People with opioid use disorders are overrepresented in correctional facilities, and are at high risk of opioid overdose. Despite the fact that buprenorphine/naloxone is the first line treatment for people with opioid use disorder, there are often institutional, clinical, and logistical barriers to buprenorphine/naloxone initiation in correctional facilities. Guided by the knowledge-to-action framework, this knowledge translation project focused on synthesizing knowledge and developing a tool for buprenorphine/naloxone initiation that was tailored to correctional facilities, including jails. This information and tool can be used to support buprenorphine/naloxone access for people in correctional facilities, in parallel with other efforts to address barriers to treatment initiation in correctional facilities.

Health Care Costs of Individuals With Chronic Psychotic Disorders Who Experience Incarceration in Ontario.

OBJECTIVE: Little is known about the health care costs of individuals with chronic psychotic disorders who experience incarceration. This study sought to address this knowledge gap. METHODS: The authors analyzed linked 2007-2010 correctional and administrative health care data on sex- and age-matched individuals with chronic psychotic disorders with and without known incarceration in prison for up to 2 years in the Ontario correctional system. Mean 1-year health care costs (overall and by sex) in the year before incarceration (when release occurred in 2010) were estimated from third-party payer data and compared between the two groups. Costs were calculated in 2018 Canadian dollars. RESULTS: Individuals who experienced incarceration (N=3,197) had mean 1-year costs of $15,728 in the year before incarceration, whereas those who did not (N=6,393) had 1-year costs of $11,588. This difference was mostly due to costs arising from psychiatric hospitalizations, emergency department visits, and physician services. The main factors associated with the difference were incarceration in the following year (increase of $4,827, p<0.001), being age 18-29 years compared with ages 30-39 or 40-49 (increase of $4,448 and $4,218, respectively, p<0.001), and chronic psychotic disorder duration of 1-2 years compared with ≤1 year duration (increase of $6,812, p=0.004). Women who experienced incarceration had higher costs than incarcerated men ($20,648 vs. $14,763). CONCLUSIONS: Individuals with chronic psychotic disorders who experienced incarceration had higher health care costs than comparable individuals who did not. These higher health care costs may signal the need for interventions and policies that help individuals with psychotic disorders avoid criminal justice system involvement.

Prevalence of Mental Health and Addiction Service use Prior to and During Incarceration in Provincial Jails in Ontario, Canada: A Retrospective Cohort Study.

OBJECTIVE: Individuals with mental illness and addiction are overrepresented in prisons. Few studies have assessed mental health and addiction (MHA)-related service use among individuals experiencing incarceration using health administrative data and most focus on service use after prison release. The objective of this study was to determine the prevalence of MHA-related service use in the 5 years prior to and during incarceration. METHODS: We used linked correctional and administrative health data for people released from Ontario provincial jails in 2010. MHA-related service use in the 5 years prior to the index incarceration was categorized hierarchically into four mutually exclusive categories based on the type of service use: psychiatric hospitalization, MHA-related emergency department (ED) visit, MHA-related outpatient visit (from psychiatrist or primary care physician), and no MHA-related service use. Demographic, diagnostic, and incarceration characteristics were compared across the four service use categories. MHA-related service use during the index incarceration was assessed by category and length of incarceration. RESULTS: A total of 48,917 individuals were included. Prior to incarceration, 6,116 (12.5%) had a psychiatric hospitalization, 8,837 (18.1%) had an MHA-related ED visit, and 15,866 (32.4%) had an MHA-related outpatient visit. Of the individuals with any MHA-related service prior to incarceration, 60.4% did not receive outpatient care from a psychiatrist prior to incarceration and 65.6% did not receive MHA-related care during incarceration. CONCLUSION: Despite a high prevalence of mental illness and addiction among people experiencing incarceration, access to and use of MHA-related care prior to and during incarceration is poor. Increasing the accessibility and use of MHA-related services throughout the criminal justice pathway is warranted.

Rates of opioid agonist treatment prescribing in provincial prisons in Ontario, Canada, 2015-2018: a repeated cross-sectional analysis.

OBJECTIVE: To describe opioid agonist treatment prescribing rates in provincial prisons and compare with community prescribing rates. DESIGN: We used quarterly, cross-sectional data on the number and proportion of people prescribed opioid agonist treatment in prison populations. Trends were compared with Ontario surveillance data from prescribers, reported on a monthly basis. SETTING: Provincial prisons and general population in Ontario, Canada between 2015 and 2018. PARTICIPANTS: Adults incarcerated in provincial prisons and people ages 15 years and older in Ontario. MAIN OUTCOMES AND MEASURES: Opioid agonist treatment prescribing prevalence, defined as treatment with methadone or buprenorphine/naloxone. RESULTS: In prison, 6.9%-8.4% of people were prescribed methadone; 0.8% to 4.8% buprenorphine/naloxone; and 8.2% to 13.2% either treatment over the study period. Between 2015 and 2018, methadone prescribing prevalence did not substantially change in prisons or in the general population. The prevalence rate of buprenorphine/naloxone prescribing increased in prisons by 1.70 times per year (95% CI 1.47 to 1.96), which was significantly higher than the increase in community prescribing: 1.20 (95% CI 1.19 to 1.21). Buprenorphine/naloxone prescribing prevalence was significantly different across prisons. CONCLUSIONS: The increase in opioid agonist treatment prescribing between 2015 and 2018 in provincial prisons shows that efforts to scale up access to treatment in the context of the opioid overdose crisis have included people who experience incarceration in Ontario. Further work is needed to understand unmet need for treatment and treatment impacts.