The association between smoking and subsequent repeated use of prescribed opioids among adolescents and young adults--a population-based cohort study.

Background: The use of prescribed opioids for chronic non-cancer pain is increasing in many countries. It is, therefore, important to investigate predictors for repeated use of opioids in young non-cancer patients.

Objective: The aim of this study was to prospectively evaluate adolescent smoking and its association with repeated use of prescription opioids in adolescents/young adults without cancer.

Methods: The study population consisted of 11,809 15-16 year old participants (86% participation rate) in the Norwegian Youth Health Surveys carried out in 2000-2003. The exposure variable, self reported smoking status, was registered in the youth surveys along with potential confounders. Repeated use of opioids, defined as 4+ prescriptions recorded in the nationwide Norwegian Prescription Database during 2004-2008, was used as outcome measure.

Results: Among the participants included in our study, 161 had redeemed 4+ prescriptions for opioids. Daily adolescent smoking was associated with repeated use of opioids with an adjusted OR of 2.2 (95% CI 1.3-3.5).

Conclusions: Daily smoking at 15-16 years of age was associated with increased risk of incident repeated use of prescribed opioids later in life. Our study suggests that smoking dependence in adolescents may predict longer lasting and/or higher levels of opioid use.