Comparison between the effects of epidural and intravenous patient-controlled analgesia on postoperative disability-free survival in patients undergoing thoracic and abdominal surgery: A post hoc analysis

Background: Thoracic epidural analgesia (TEA) and intravenous patient-controlled analgesia (IV-PCA) are widely used to mitigate immediate postoperative pain; however, their effects on long-term disability-free survival are poorly documented. This study aimed to compare the effects of postoperative TEA and IV-PCA on disability-free survival in patients who underwent thoracic or abdominal surgery.

Methods: This post hoc analysis of a prospective observational study included 845 inpatients aged ≥55 years that underwent elective thoracic and abdominal surgery between 1 April 2016 and 28 December 2018 in a tertiary care hospital. Inverse probability of treatment weighted (IPTW) using stabilized inverse propensity scores was adopted to minimize bias. The primary outcome in this study was disability-free survival, defined as survival with a 12-item World Health Organization Disability Assessment Schedule 2.0 score of <16%, assessed at 3 months and 1 year after surgery.

Results: The final analysis included 601 patients who received TEA and 244 who received IV-PCA. After IPTW, the weighted incidence of disability-free survival at 3 months and 1 year was 60.5% and 61.4% in the TEA group and 78.3% and 66.2% in the IV-PCA group, respectively. The adjusted OR for disability-free survival at 3 months and 1 year was 0.84 (95% confidence interval [CI]: 0.50-1.39) and 1.21 (95% CI: 0.72-2.05), respectively, for the TEA group.

Conclusion: No significant differences were observed in the disability-free survival at 3 months and 1 year after elective thoracic and abdominal surgery in patients aged ≥55 years who received TEA or IV-PCA.

Significance statement: This study is the first in our setting to document the long-term effects of patient-controlled analgesia. In a post hoc analysis of our prospective cohort study, we show that although differences in chronic postsurgical pain exist at 3 months post-surgery, disability-free survival rates at 1 year do not differ irrespective of the choice of patient-controlled analgesia. The findings of this study highlight the need for shared decision-making between clinicians and patients.