Heather Palis1, Daphne Guh2, Scott MacDonald3, Scott Harrison3, Suzanne Brissette4, David C Marsh5, Martin T Schechter6, Eugenia Oviedo-Joekes6. 1. Centre for Health Evaluation & Outcome Sciences, Providence Health Care, St. Paul's Hospital, 575- 1081 Burrard St., Vancouver, BC, V6Z 1Y6, Canada; School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, BC, V6T 1Z3, Canada. Electronic address: hpalis@cheos.ubc.ca. 2. School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, BC, V6T 1Z3, Canada. 3. Providence Health Care, Providence Crosstown Clinic, 84 West Hastings Street, Vancouver, BC, V6B 1G6, Canada. 4. Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 St-Denis, Montréal, QC, H2X 0A9, Canada. 5. Northern Ontario School of Medicine, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada; Canadian Addiction Treatment Centres, 175 Commerce Valley West, Suite 300, Markham, Ontario, L3T 7P6, Canada; ICES North, 41 Ramsey Lake Rd, Sudbury, ON, P3E 5J1, Canada; Health Sciences North Research Institute, 56 Walford Rd, Sudbury, ON, P3E 2H2, Canada. 6. Centre for Health Evaluation & Outcome Sciences, Providence Health Care, St. Paul's Hospital, 575- 1081 Burrard St., Vancouver, BC, V6Z 1Y6, Canada; School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, BC, V6T 1Z3, Canada.
Abstract
BACKGROUND AND AIMS: Cocaine use is prevalent among people receiving injectable opioid agonist treatment. Investigations of cocaine use in this population have been descriptive and the potential heterogeneity existing in patterns of use have not been characterized. As such, among patients receiving injectable opioid agonist treatment, this study aimed to: 1) quantify intra- and inter-individual variation in cocaine use over 24-months and; 2) determine how predictors of interest explained this variation. METHODS: Participants were patients receiving injectable opioid agonist treatment for opioid use disorder. Study visits were completed at baseline prior to receiving treatment, and 3,6,9,12,18, and 24 months after baseline. A multi-level regression approach to growth curve modeling was employed to estimate and explain intra- (within-person) and inter-individual (between-person) variation in cocaine use. RESULTS: Significant intra and inter-individual variation in cocaine use was identified over 24-months. Treatment engagement was on average associated with reductions in the prior month number of days of cocaine use (range: 0-30)(Estimate (standard error): -0.05(0.02), p = 0.003). On average, men reported less cocaine use compared to women (Estimate (standard error): -5.91(1.57), p=<0.001), and participants reporting ever regularly using cocaine at baseline reported more cocaine use over 24-months compared to participants reporting never regularly using cocaine (Estimate (standard error): 4.72 (1.91), p = 0.013). CONCLUSIONS: Significant reductions in cocaine use were observed and significant heterogeneity in patterns of cocaine use was identified. These heterogeneous cocaine use profiles suggest that an individualized approach to care will be critical in responding to patients' cocaine use in injectable opioid agonist treatment.
BACKGROUND AND AIMS: Cocaine use is prevalent among people receiving injectable opioid agonist treatment. Investigations of cocaine use in this population have been descriptive and the potential heterogeneity existing in patterns of use have not been characterized. As such, among patients receiving injectable opioid agonist treatment, this study aimed to: 1) quantify intra- and inter-individual variation in cocaine use over 24-months and; 2) determine how predictors of interest explained this variation. METHODS:Participants were patients receiving injectable opioid agonist treatment for opioid use disorder. Study visits were completed at baseline prior to receiving treatment, and 3,6,9,12,18, and 24 months after baseline. A multi-level regression approach to growth curve modeling was employed to estimate and explain intra- (within-person) and inter-individual (between-person) variation in cocaine use. RESULTS: Significant intra and inter-individual variation in cocaine use was identified over 24-months. Treatment engagement was on average associated with reductions in the prior month number of days of cocaine use (range: 0-30)(Estimate (standard error): -0.05(0.02), p = 0.003). On average, men reported less cocaine use compared to women (Estimate (standard error): -5.91(1.57), p=<0.001), and participants reporting ever regularly using cocaine at baseline reported more cocaine use over 24-months compared to participants reporting never regularly using cocaine (Estimate (standard error): 4.72 (1.91), p = 0.013). CONCLUSIONS: Significant reductions in cocaine use were observed and significant heterogeneity in patterns of cocaine use was identified. These heterogeneous cocaine use profiles suggest that an individualized approach to care will be critical in responding to patients' cocaine use in injectable opioid agonist treatment.