The cascade of care for opioid use disorder among youth in British Columbia, 2018.

BACKGROUND: Medication for opioid use disorder (MOUD) is associated with substantial reductions in the risk of mortality, and American and Canadian guidelines recommend it as part of the full range of available treatments for youth with opioid use disorder (OUD). We estimated the OUD cascade of care for all adolescents (ages 12-18) and young adults (19-24) with OUD in British Columbia, Canada (BC) in 2018. METHODS: Using a provincial-level linkage of six health administrative databases, we classified youth with OUD as adolescents (ages 12-18) or young adults (19-24) to compare with older adults (≥25) and described key factors known to influence engagement in health care. The eight-stage cascade of care included diagnosed with OUD, ever engaged in MOUD, recently in MOUD, currently in MOUD, and retained in MOUD for ≥1 month, ≥3 months, ≥12 months, ≥24 months. RESULTS: We identified 4048 youth diagnosed with OUD as of September 30, 2018 (6.3% of all people with OUD). Most were young adults, aged 19-24 (n = 3602; 89.0% of all youth), a majority of whom were males (n = 1984; 55.1%). In contrast, adolescents diagnosed with OUD (n = 446; 11.0% of all youth) were mostly females (n = 287; 64.4%). Compared to adolescents, there were more young adults diagnosed with OUD ever engaged in MOUD (71.4% v. 36.5%), currently on MOUD (29.3% v. 16.8%), and retained in care for ≥1 year (8.6% v. 2.0%). CONCLUSIONS: A high proportion of youth aged 12-24 diagnosed with OUD in a health care setting in British Columbia received MOUD yet continued engagement is infrequent, particularly for adolescents. Long-term treatment plans for youth need to consider including MOUD when appropriate as part of tailored, youth-friendly services.

Diagnosis of Opioid Use Disorder by Youths Assessed in Acute Care Settings in British Columbia, Canada.

OBJECTIVES: To describe trends in the number of youths diagnosed with opioid use disorder (OUD) and to identify factors associated with OUD diagnosis in acute care settings. STUDY DESIGN: Data from a population-based retrospective cohort study with linkage of 6 health administrative databases for 13 009 youth age 12-24 years identified with OUD between 2001 and 2018 in British Columbia, Canada were used to describe annual diagnoses. Using a multiple logistic regression model, we estimated the association between past-year health care utilization and OUD diagnosis in acute settings, controlling for sociodemographic and OUD-related comorbid conditions. RESULTS: Annual OUD diagnoses quadrupled between 2003 and 2017 (from 326 to 1473). Among the 6579 youth diagnosed with OUD between April 1, 2013 and September 30, 2018, 88.1% had past-year health system contacts. Youth age 12-18 had higher odds of OUD diagnosis in acute care (aOR 2.04; 95% CI 1.78, 2.34). Compared with no health care contact, youth receiving outpatient care only were less likely to be diagnosed with OUD in acute care (aOR 0.69; 95% CI 0.56, 0.84) and those with >1 urgent hospitalization were more likely to be diagnosed with OUD in acute care (aOR 1.87; 95% CI 1.40,2.49). CONCLUSIONS: More than 88% of youth had past-year health system contacts prior to diagnosis. Those age 12-18 years and with urgent hospitalizations in the year prior to diagnosis were more likely to have OUD diagnosed in acute care settings. Establishing an effective evidence-based system for early detection and intervention among youth with OUD must be a priority.

Estimates of opioid use disorder prevalence from a regression-based multi-sample stratified capture-recapture analysis.

BACKGROUND: An epidemic of opioid overdose has spread across North America, with illicit drug-related overdose emerging as a leading cause of death in recent years. Estimates of opioid use disorder (OUD) prevalence at the level of the public health service delivery area are needed to project resource needs and identify priority areas for targeted intervention. Our objective is to estimate the annual prevalence of OUD in British Columbia (BC), Canada, from 2000 to 2017. METHODS: We performed a multi-sample stratified capture-recapture analysis to estimate OUD prevalence in BC. The analysis included individuals identified from 3 administrative databases for 2000-2011 and 4 databases for 2012-2017, linked at the individual level. Negative binomial regression models on the counts of individuals within these strata were used to estimate prevalence, adjusting for dependency between databases. RESULTS: OUD prevalence in BC among people aged 12 years or older was 1.00 % (N = 34,663 individuals) in 2000 and increased to 1.54 % (N = 61,080) in 2011. Between 2013 and 2017 prevalence increased from 1.57 % (95 % confidence interval: 1.56-1.58) to 1.92 % (1.89-1.95; N = 83,760; 82,492-84,855). The greatest increases in prevalence were observed among males 12-30 years old and 31-44 years old, with 43.2 % and 40.2 % increases from 2013 to 2017. CONCLUSIONS: In BC, the OUD prevalence was 1.92 % among people 12 years or older in 2017. We estimated that prevalence has nearly doubled since 2000, with the highest increases in prevalence observed among males under 45.

Opioid agonist treatment and risk of mortality during opioid overdose public health emergency: population based retrospective cohort study.

OBJECTIVE: To compare the risk of mortality among people with opioid use disorder on and off opioid agonist treatment (OAT) in a setting with a high prevalence of illicitly manufactured fentanyl and other potent synthetic opioids in the illicit drug supply. DESIGN: Population based retrospective cohort study. SETTING: Individual level linkage of five health administrative datasets capturing drug dispensations, hospital admissions, physician billing records, ambulatory care reports, and deaths in British Columbia, Canada. PARTICIPANTS: 55 347 people with opioid use disorder who received OAT between 1 January 1996 and 30 September 2018. MAIN OUTCOME MEASURES: All cause and cause specific crude mortality rates (per 1000 person years) to determine absolute risk of mortality and all cause age and sex standardised mortality ratios to determine relative risk of mortality compared with the general population. Mortality risk was calculated according to treatment status (on OAT, off OAT), time since starting and stopping treatment (1, 2, 3-4, 5-12, >12 weeks), and medication type (methadone, buprenorphine/naloxone). Adjusted risk ratios compared the relative risk of mortality on and off OAT over time as fentanyl became more prevalent in the illicit drug supply. RESULTS: 7030 (12.7%) of 55 347 OAT recipients died during follow-up. The all cause standardised mortality ratio was substantially lower on OAT (4.6, 95% confidence interval 4.4 to 4.8) than off OAT (9.7, 9.5 to 10.0). In a period of increasing prevalence of fentanyl, the relative risk of mortality off OAT was 2.1 (95% confidence interval 1.8 to 2.4) times higher than on OAT before the introduction of fentanyl, increasing to 3.4 (2.8 to 4.3) at the end of the study period (65% increase in relative risk). CONCLUSIONS: Retention on OAT is associated with substantial reductions in the risk of mortality for people with opioid use disorder. The protective effect of OAT on mortality increased as fentanyl and other synthetic opioids became common in the illicit drug supply, whereas the risk of mortality remained high off OAT. As fentanyl becomes more widespread globally, these findings highlight the importance of interventions that improve retention on opioid agonist treatment and prevent recipients from stopping treatment.

The cascade of care for opioid use disorder: a retrospective study in British Columbia, Canada.

BACKGROUND AND AIMS: The 'cascade of care' framework, measuring attrition at various stages of care engagement, has been proposed to guide the public health response to the opioid overdose public health emergency in British Columbia, Canada. We estimated the cascade of care for opioid use disorder and identified factors associated with care engagement for people with opioid use disorder (PWOUD) provincially. DESIGN: Retrospective study using a provincial-level linkage of four health administrative databases. SETTING AND PARTICIPANTS: All PWOUD in BC from 1 January 1996 to 30 November 2017. MEASUREMENTS: The eight-stage cascade of care included diagnosed PWOUD, ever on opioid agonist treatment (OAT), recently on OAT, currently on OAT and retained on OAT: ≥ 1, ≥ 3, ≥ 12 and ≥ 24 months). Health-care use, homelessness and other demographics were obtained from physician billing records, hospitalizations, and drug dispensation records. Receipt of income assistance was indicated by enrollment in Pharmacare Plan C. FINDINGS: A total of 55 470 diagnosed PWOUD were alive at end of follow-up. As of 2017, a majority of the population (n = 39 456; 71%) received OAT during follow-up; however, only 33% (n = 18 519) were currently engaged in treatment and 16% (n = 8960) had been retained for at least 1 year. Compared with those never on OAT, those currently engaged in OAT were more likely to be aged under 45 years [adjusted odds ratio (aOR) = 1.75, 95% confidence interval (CI) = 1.64, 1.89], male (aOR = 1.72, 95% CI = 1.64, 1.82), with concurrent substance use disorders (aOR = 2.56, 95% CI = 2.44, 2.70), hepatitis C virus (HCV) (aOR = 1.22, 95% CI = 1.14, 1.33) and either homeless or receiving income-assistance (aOR = 4.35, 95% CI = 4.17, 4.55). Regular contact with the health-care system-either in out-patient or acute care settings-was common among PWOUD not engaged in OAT, regardless of time since diagnosis or treatment discontinuation. CONCLUSIONS: People with opioid use disorder in British Columbia, Canada show high levels of out-patient care prior to diagnosis. Younger age, male sex, urban residence, lower income level and homelessness appear to be independently associated with increased opioid agonist treatment engagement.

Differing profiles of people diagnosed with acute and chronic hepatitis B virus infection in British Columbia, Canada.

AIM: To describe the characteristics of people diagnosed with acute and chronic hepatitis B virus (HBV) infection in British Columbia (BC). METHODS: We used data from the BC Hepatitis Testers Cohort (BC-HTC), which includes all individuals tested for hepatitis C virus (HCV) or human immunodeficiency virus (HIV) or those diagnosed with HBV or active tuberculosis in BC since 1990. These data were integrated with prescription drug, medical visit, hospitalization and mortality data. HBV cases were classified as acute or chronic according to provincial guidelines. We compared characteristics of individuals by HBV infection group (acute, chronic and negative). Factors associated with acute or chronic HBV infection were assessed with multinomial logistic regression models in comparison to the HBV negative group. RESULTS: 46498 of the 1058056 eligible BC-HTC participants were diagnosed with HBV infection. 4.3% of HBV positive individuals were diagnosed with acute HBV infections while 95.7% had chronic infections. Problematic alcohol use, injection drug use, and HIV or HCV co-infection were more common among individuals diagnosed with acute HBV compared to those with chronic infections and HBV negative individuals. In multivariable multinomial logistic regression models, we observed significant associations between acute or chronic HBV diagnosis and being male, age at HBV diagnosis or birth cohort, South and East Asian ethnicity, HCV or HIV infection, and injection drug use. The odds of acute HBV decreased with increasing age among people who inject drugs, while the opposite was true for chronic HBV. Persons with acute HBV were predominantly White (78%) while those with chronic HBV were mostly East Asian (60%). Relative to Whites, East Asians had 12 times greater odds of being diagnosed with chronic HBV infection. These odds increased with increasing socioeconomic deprivation. CONCLUSION: Differences in the profiles of people diagnosed with acute and chronic HBV infection necessitate differentiated screening, prevention, care and treatment programs.