FACTORS ASSOCIATED WITH ADHERENCE TO OPIOID AGONIST THERAPY IN ONTARIO: A LONGITUDINAL POPULATION-BASED STUDY (2014-2022)
Author(s)
Shreedhar Acharya, MSc, MSPH;
Northern Ontario School of Medicine, Sudbury, ON, Canada
Northern Ontario School of Medicine, Sudbury, ON, Canada
OBJECTIVES: Opioid Agonist Therapy (OAT) is an effective treatment for opioid use disorder (OUD), and includes methadone, buprenorphine, slow-release oral morphine (SROM), and extended-release buprenorphine (XR-BUP). This study aimed to identify factors associated with OAT adherence in Ontario, Canada.
METHODS: We conducted a retrospective cohort study using linked, population-based administrative healthcare databases from January 1, 2014, to December 31, 2022. OAT adherence was measured using the proportion of days covered (PDC), utilizing the Narcotics Monitoring System (NMS) databases. A total of 58,953 individuals aged ≥15 years who initiated OAT during the study period, contributing 3.31 million monthly PDC observations analyzed using a Generalized Estimating Equation (GEE) model.
RESULTS: The cohort included 48,547 (82.5%) patients from Southern Ontario and 9,946 (17.5%) from Northern Ontario. The average monthly proportion of days covered (PDC) across the province was 0.56, with a median of 0.81. Female OAT patients demonstrated slightly but significantly lower treatment adherence (PDC) compared to male patients in Ontario (β = -0.0038, 95% CI: -0.0070 to -0.0007, p < 0.018). Patients residing in Northern Ontario demonstrated lower PDC compared with those living in Southern Ontario, but the result is not statistically significantly different (β = -0.0027, 95% CI: -0.0117 to 0.0064, p = 0.563). However, after adjusting for covariates, greater geographic remoteness was significantly associated with higher PDC (β = 0.0475, 95% CI: 0.0289 to 0.0662, p < 0.001). Patients with a history of homelessness, hepatitis C infection, HIV positivity, or any mental health diagnosis exhibited significantly lower PDC compared to their respective reference groups.
CONCLUSIONS: In conclusion, treatment adherence is influenced by sociodemographic factors, some comorbidity conditions, and geographic factors. Recognizing these disparities is essential for developing tailored interventions to enhance OAT adherence and improve overall treatment outcomes across Ontario.
METHODS: We conducted a retrospective cohort study using linked, population-based administrative healthcare databases from January 1, 2014, to December 31, 2022. OAT adherence was measured using the proportion of days covered (PDC), utilizing the Narcotics Monitoring System (NMS) databases. A total of 58,953 individuals aged ≥15 years who initiated OAT during the study period, contributing 3.31 million monthly PDC observations analyzed using a Generalized Estimating Equation (GEE) model.
RESULTS: The cohort included 48,547 (82.5%) patients from Southern Ontario and 9,946 (17.5%) from Northern Ontario. The average monthly proportion of days covered (PDC) across the province was 0.56, with a median of 0.81. Female OAT patients demonstrated slightly but significantly lower treatment adherence (PDC) compared to male patients in Ontario (β = -0.0038, 95% CI: -0.0070 to -0.0007, p < 0.018). Patients residing in Northern Ontario demonstrated lower PDC compared with those living in Southern Ontario, but the result is not statistically significantly different (β = -0.0027, 95% CI: -0.0117 to 0.0064, p = 0.563). However, after adjusting for covariates, greater geographic remoteness was significantly associated with higher PDC (β = 0.0475, 95% CI: 0.0289 to 0.0662, p < 0.001). Patients with a history of homelessness, hepatitis C infection, HIV positivity, or any mental health diagnosis exhibited significantly lower PDC compared to their respective reference groups.
CONCLUSIONS: In conclusion, treatment adherence is influenced by sociodemographic factors, some comorbidity conditions, and geographic factors. Recognizing these disparities is essential for developing tailored interventions to enhance OAT adherence and improve overall treatment outcomes across Ontario.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
PCR88
Topic
Patient-Centered Research
Topic Subcategory
Adherence, Persistence, & Compliance, Patient Engagement
Disease
No Additional Disease & Conditions/Specialized Treatment Areas