Influential factors of postoperative pain trajectories in patients receiving intravenous patient-controlled analgesia: a single-centre cohort study in Taiwan

ObjectivesWe aimed to investigate the factors associated with variations in postoperative pain trajectories over time in patients using intravenous patient-controlled analgesia (IV-PCA) for postoperative pain.DesignRetrospective cohort study.SettingA single medical centre in Taiwan.ParticipantsPatients receiving IV-PCA after surgery.Primary and secondary outcome measuresPrimary outcome was the postoperative pain scores.ResultsA total of 3376 patients and 20 838 pain score observations were analysed using latent curve models. Female and longer anaesthesia time increased the baseline level of pain (p=0.004 and 0.003, respectively), but abdominal surgery and body weight decreased it (both p