Opioid Injection Prescription Rates Over an Eight-Year Period for the Non-Cancer Patients in South Korea: A Population-Based Study

The objective of this study was to assess opioid injections prescription rate in Korea. This study utilized the National Health Insurance Service-National Sample Cohort data. The general population consisted of non-cancer outpatients with at least one injection prescription, and the opioid population consisted of non-cancer outpatients with at least one opioid injection prescription from 2008 to 2015. We calculated the total injection rate by dividing the number of injection prescriptions by the number of outpatient visits. The opioid injection rate was calculated similarly, using only opioid injection prescriptions. Stratification was based on sex, age, institution location, and type, with annual trends assessed using the Cochran-Armitage test. Opioid-injections constituted 24.62% of total injection prescriptions. Over the eight years, tramadol was the most frequently prescribed opioid, accounting for approximately 98% of opioid-injection prescriptions. Of tramadol, 93% was prescribed in the clinic, primarily to treat inflammatory-related conditions. The total injection rates for the opioid population were significantly higher than those for the general population during all time periods (27.39% vs. 35.51% in 2015, p<0.001). Although the opioid injection rate decreased from 9.10% in 2008 to 7.20% in 2015 (p<0.001), the proportion of opioid-injections among the total injection prescriptions remained relatively consistent. Opioid injection rates were notably higher among females, elderly, rural residents, and clinic visits (p<0.001). Despite the ongoing decline in Korea’s annual opioid prescription rates, the seriousness of this matter cannot be underestimated. Further investigations are imperative to ascertain whether the prescription of opioid injections correlates with an elevated risk of opioid abuse.