ASSOCIATION BETWEEN MENTAL DISORDERS AND OPIOID MISUSE AMONG PATIENTS WITH OPIOID PRESCRIPTION: A NATIONWIDE COHORT STUDY IN SOUTH KOREA
Author(s)
Soomi Jo, BS1, Hae Sun Suh, MA, MS, PhD2.
1Department of Regulatory Science, Graduate School, Kyunghee University, Seoul, Korea, Republic of, 2College of Pharmacy, Kyung Hee University, Seoul, Korea, Republic of.
1Department of Regulatory Science, Graduate School, Kyunghee University, Seoul, Korea, Republic of, 2College of Pharmacy, Kyung Hee University, Seoul, Korea, Republic of.
OBJECTIVES: To evaluate whether newly diagnosed mental disorders are associated with an increased risk of subsequent opioid misuse among patients initiating opioid therapy in South Korea.
METHODS: This nationwide retrospective cohort study used the Korean Health Insurance Review and Assessment Service (HIRA) database (2022-2024). Adult patients newly prescribed opioids between July 2023 and December 2024 were included. Exposure was defined as a newly diagnosed mental disorder within 180 days before opioid initiation, identified using ICD-10 codes F12-F19, F20, F29, F31-F34, F40-F48, F51, F60, and F90. Patients with prior mental disorder diagnoses within one year before the index diagnosis and those with opioid prescriptions during the one-year washout period before opioid initiation were excluded. Opioid misuse was defined as visiting ≥4 medical institutions within 90 days for opioid prescriptions or having ≥25% overlapping days supplied of the same opioid. Stabilized inverse probability of treatment weighting (IPTW) balanced baseline characteristics, and Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs).
RESULTS: A total of 4,591,566 new opioid users were included, of whom 409,835 (8.92%) had a newly diagnosed mental disorder after opioid initiation. After IPTW adjustment, baseline characteristics were well balanced between groups (all standardized mean differences <0.1). During a median follow-up of 11.86 months, 104,948 patients developed opioid misuse. The incidence rate of misuse was 30.40 and 22.33 per 1,000 person-years among patients with and without mental disorders, respectively. In the IPTW-adjusted Cox model, mental disorders were associated with an increased risk of opioid misuse (HR, 1.06; 95% CI, 1.04-1.08).
CONCLUSIONS: Newly diagnosed mental disorders after opioid initiation were significantly associated with a higher risk of subsequent opioid misuse among new opioid users in South Korea. These findings highlight the importance of early identification and monitoring of mental health conditions following opioid initiation to reduce the risk of opioid misuse.
METHODS: This nationwide retrospective cohort study used the Korean Health Insurance Review and Assessment Service (HIRA) database (2022-2024). Adult patients newly prescribed opioids between July 2023 and December 2024 were included. Exposure was defined as a newly diagnosed mental disorder within 180 days before opioid initiation, identified using ICD-10 codes F12-F19, F20, F29, F31-F34, F40-F48, F51, F60, and F90. Patients with prior mental disorder diagnoses within one year before the index diagnosis and those with opioid prescriptions during the one-year washout period before opioid initiation were excluded. Opioid misuse was defined as visiting ≥4 medical institutions within 90 days for opioid prescriptions or having ≥25% overlapping days supplied of the same opioid. Stabilized inverse probability of treatment weighting (IPTW) balanced baseline characteristics, and Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs).
RESULTS: A total of 4,591,566 new opioid users were included, of whom 409,835 (8.92%) had a newly diagnosed mental disorder after opioid initiation. After IPTW adjustment, baseline characteristics were well balanced between groups (all standardized mean differences <0.1). During a median follow-up of 11.86 months, 104,948 patients developed opioid misuse. The incidence rate of misuse was 30.40 and 22.33 per 1,000 person-years among patients with and without mental disorders, respectively. In the IPTW-adjusted Cox model, mental disorders were associated with an increased risk of opioid misuse (HR, 1.06; 95% CI, 1.04-1.08).
CONCLUSIONS: Newly diagnosed mental disorders after opioid initiation were significantly associated with a higher risk of subsequent opioid misuse among new opioid users in South Korea. These findings highlight the importance of early identification and monitoring of mental health conditions following opioid initiation to reduce the risk of opioid misuse.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
EPH177
Topic
Epidemiology & Public Health, Real World Data & Information Systems
Topic Subcategory
Safety & Pharmacoepidemiology
Disease
Mental Health (including addiction)