New, long-term opioid use after lung cancer surgery is associated with reduced 2-year survival: a retrospective population-based cohort study in South Korea

Introduction We aimed to investigate the proportion and associated factors for new long-term opioid use and its long-term effects after lung cancer surgery. Methods The South Korean National Health Insurance Database was used as a nationwide registration data source. All patients undergoing lung cancer surgery between 2011 and 2018 were included, and patients who were preoperative opioid users were excluded from the analysis. New long-term opioid use was defined as an active opioid prescription at 6 months postoperatively. Results In total, 54 509 patients were included in the final analysis. At 6 months postoperatively, 3325 (6.1%) patients who were newly prescribed opioids comprised the new long-term opioid user group. Older age, male sex, wider surgical extent, open thoracotomy, increased Charlson Comorbidity Index score, neoadjuvant or adjuvant chemotherapy, preoperative anxiety disorder and insomnia disorder were associated with a higher rate of new long-term opioid use. The new long-term opioid user group showed a 40% (HR, 1.40; 95% CI 1.29 to 1.53; p<0.001) higher risk of 2-year all-cause mortality. Moreover, the new long-term potent opioid user and less potent opioid user groups showed a 92% (HR, 1.92; 95% CI 1.67 to 2.21; p<0.001) and 22% (HR, 1.22; 95% CI 1.10 to 1.36; p<0.001) higher risk of 2-year all-cause mortality, respectively. Conclusions Among preoperative opioid-naive patients in South Korea, 6.1% became new long-term opioid users after lung cancer surgery. Certain factors are potential risk factors for new long-term opioid use, which could be associated with poorer long-term survival outcomes.