A Prospective Study to Investigate Predictors of Relapse among Patients with Opioid Use Disorder Treated with Methadone.
BACKGROUND
Concomitant opioid abuse is a serious problem among patients receiving methadone maintenance treatment (MMT) for opioid use disorder. This is an exploratory study that aims to identify predictors of the length of time a patient receiving MMT for opioid use disorder remains abstinent (relapse-free).


METHODS
Data were collected from 250 MMT patients enrolled in addiction treatment clinics across Southern Ontario. The impact of certain clinical and socio-demographic factors on the outcome (time until opioid relapse) was determined using a Cox proportional hazard model.


RESULTS
History of injecting drug use behavior (hazard ratio (HR): 2.26, P = 0.042), illicit benzodiazepine consumption (HR: 1.07, P = 0.002), and the age of onset of opioid abuse (HR: 1.10, P < 0.0001) are important indicators of accelerated relapse among MMT patients. Conversely, current age is positively associated with duration of abstinence from illicit opioid use, serving as a protective factor against relapse (HR: 0.93, P = 0.003).


CONCLUSIONS
This study helps to identify patients at increased risk of relapse during MMT, allowing health care providers to target more aggressive adjunct therapies toward high-risk patients.
Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada.
Leen
L
Naji
St. George's University of London, London, United Kingdom.; Department of Clinical Epidemiology and Biostatistics, McMaster University, ON, Hamilton, Canada.
Brittany B
BB
Dennis
St. George's University of London, London, United Kingdom.
Monica
M
Bawor
Canadian Addiction Treatment Centre, Richmond Hill, ON, Canada.
Carolyn
C
Plater
Department of Clinical Epidemiology and Biostatistics, McMaster University, ON, Hamilton, Canada.
Guillaume
G
Pare
Canadian Addiction Treatment Centre, Richmond Hill, ON, Canada.; Department of Medicine, Hamilton General Hospital, Hamilton, ON, Canada.
Andrew
A
Worster
Canadian Addiction Treatment Centre, Richmond Hill, ON, Canada.
Michael
M
Varenbut
Canadian Addiction Treatment Centre, Richmond Hill, ON, Canada.
Jeff
J
Daiter
Canadian Addiction Treatment Centre, Richmond Hill, ON, Canada.; Northern Ontario School of Medicine, Sudbury, ON, Canada.
David C
DC
Marsh
Population Genomics Program, Chanchlani Research Center, McMaster University, Hamilton, ON, Canada.
Dipika
D
Desai
Department of Clinical Epidemiology and Biostatistics, McMaster University, ON, Hamilton, Canada.; Centre for Evaluation of Medicine, Hamilton, ON, Canada.; System Linked Research Unit, Hamilton, ON, Canada.
Lehana
L
Thabane
Department of Clinical Epidemiology and Biostatistics, McMaster University, ON, Hamilton, Canada.; Population Genomics Program, Chanchlani Research Center, McMaster University, Hamilton, ON, Canada.; Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada.; Peter Boris Centre for Addictions Research, St. Joseph's Healthcare Hamilton, Hamilton, ON, Canada.
Zainab
Z
Samaan
methadone; opioid relapse; opioid substitution treatment; opioid use disorder; substance abuse