Prevalence and Its Correlation with Sustained Opioid Use in Korea: A Group-Based Trajectory Analysis.

Long-term use of opioid analgesics can lead to addiction and opioid-related death. We aimed to present the pattern of long-term opioid utilization and identify factors associated with it by using group-based trajectory modeling. We used the nationwide health insurance claims database from 2009 to 2013. Multinomial logistic regression was conducted to estimate the adjusted odds ratio (aOR) and its 95% confidence intervals (CI) for the risk of sustained opioid use associated with various clinical factors. Among 15,327 patients prescribed with opioids, three trajectories were identified: high-sustained users (4.6%, n = 713), early discontinuation (84.2%, n = 12,916), and slow discontinuation (11.2%, n = 1,698). A higher proportion of women (72.8% vs. 58.4%) and elderly patients (55.9% vs. 22.1%) were found in the high-sustained users than the early discontinuation group. Depression (aOR 3.55, 95% CI 1.99-6.35) and epilepsy (aOR 10.12, CI 4.72-21.67) were the two highest comorbidities associated with sustained opioid use in the high-sustained users when compared to the early discontinuation group. Among chronic non-cancer patients, 4.6% were prescribed opioids consistently. Both healthcare providers and patients should be aware of the factors associated with sustained opioid use when prescribing it to patients with mental-related conditions, and its consequent adverse events should be carefully monitored.