Patient recruitment
depression, pain
SECONDARY, RECRUITMENT
The patients recruited in this study were originally consented to participate in a randomized controlled trial on evaluating the association between labor epidural analgesia and postpartum depression (primary study), with the outcome being the incidence of postpartum depression at 6–10 weeks after delivery. Patient recruitment and follow-up for the primary study has been completed with ongoing data analysis. This study is the secondary analysis by using the trial as a platform to investigate the pain components, of which the pain outcomes were not relevant to the primary objective of the trial. The study was reviewed and approved by SingHealth Centralized Institutional Review Board (Ref no. 2017/2090) on 25/03/2017, with registration on Clinicaltrials.gov (NCT03167905) on 30/05/2017. All patients were recruited from June 2017 to July 2021 with written informed consent obtained from all participants on the primary trial, and patients were informed that the data obtained would be used for further analysis such as this study. This manuscript adheres to the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guidelines.The study population included women with American Society of Anesthesiologists (ASA) physical status II [