Gender differences in mortality among treated opioid dependent patients.
OBJECTIVE
To assess gender differences in characteristics, mortality rates, and the causes and predictors of death among treated opioid-dependent individuals.


METHODS
Linked vital statistics data were obtained for all individuals first enrolled in publicly funded pharmacological treatment for opioid dependence in California from 2006 to 2010. Standardized mortality ratios (SMR) were calculated by gender. Cox proportional hazards models with time-varying covariates were fitted to determine the effect of gender on the hazard of all-cause mortality, controlling for covariates.


RESULTS
Over a median 2.6 years (interquartile range: 1.4-3.7), 1.031 deaths were observed, including 2.2% (259/11,564) of women and 3.7% (772/20,758) of men. Women had a greater increased risk of mortality compared to the general population (SMR 5.1 95% CI: 4.5, 5.7) than men (SMR 4.3 95% CI: 4.0, 4.6). The relative risk of death for women compared with men was 1.18 (95% CI: 1.02, 1.36). Women had a lower instantaneous hazard of all-cause mortality than men (HR 0.58, 95% CI 0.50, 0.68), controlling for other factors. Significant interaction effects indicated that among men, mortality risk was decreased by full-time employment and increased by non-daily heroin use (relative to daily use) and medical problems. Concurrent opioid and methamphetamine/cocaine use increased mortality risk among women and decreased it among men.


CONCLUSIONS
Treatment for opioid dependence is likely to reduce mortality risk among men by addressing employment and medical problems, and via interventions to reduce overdose risk after heroin abstinence, and among women by attending to the concurrent use of methamphetamine/cocaine and opioids.
UCLA Integrated Substance Abuse Programs, United States. Electronic address: laevans@ucla.edu.
E
E
Evans
UCLA Integrated Substance Abuse Programs, United States.
A
A
Kelleghan
UCLA Integrated Substance Abuse Programs, United States.
L
L
Li
British Columbia Centre for Excellence in HIV/AIDS, Canada.
J
J
Min
UCLA Integrated Substance Abuse Programs, United States.
D
D
Huang
UCLA Integrated Substance Abuse Programs, United States.
D
D
Urada
UCLA Integrated Substance Abuse Programs, United States.
Y I
YI
Hser
British Columbia Centre for Excellence in HIV/AIDS, Canada; Simon Fraser University, Faculty of Health Sciences, Canada.
B
B
Nosyk
D000328:Adult; D002140:California; D005260:Female; D006801:Humans; D008297:Male; D009293:Opioid-Related Disorders / Q000188:drug therapy* / Q000401:mortality*; D016016:Proportional Hazards Models; D012307:Risk Factors; D012727:Sex Characteristics; D012737:Sex Factors; D055815:Young Adult
Detoxification treatment; Gender differences; Longitudinal; Methadone treatment; Mortality; Opioid dependence