New onset postoperative depression after major surgery: an analysis from a national claims database

Background: Postoperative depression is not well characterised. We investigated the incidence of postoperative depression with the hypothesis that after controlling for confounders, new onset depression would vary significantly by surgical type. Methods: We conducted a retrospective cohort study using the Optum Clinformatics Datamart. The primary outcome was new onset postoperative depression, defined by a new diagnosis of depression or new prescription for an antidepressant in the year after surgery using International Classification of Diseases (ICD) 9/10 codes and drug names. Adjustment for preoperative comorbidities and predictors of depression was with multivariable Cox regression and propensity score matching. Sensitivity analyses defining new onset depression as both a new diagnosis of depression and a new prescription for an antidepressant, or either outcome separately, were conducted. Results: Data from 132 390 cardiac surgery, 12 538 thoracotomy, 32 630 video-assisted thoracoscopic surgery (VATS), 96 750 hip fracture surgery, 157 484 hip replacement, and 347 878 laparoscopic cholecystectomy patients from January 2004 to June 2021 were analysed. The incidence of new onset postoperative depression was 18.8% for hip fracture surgery, 16.1% for thoracotomy, 12.6% for cardiac surgery, 12.4% for VATS, 8.6% for laparoscopic cholecystectomy, and 6.8% for hip replacement. After multivariable adjustment, hip fracture surgery patients were most likely to develop new onset postoperative depression (hazard ratio [95% confidence interval]) 1.56 [1.45–1.68]), followed by thoracotomy (1.12 [1.03–1.22]), cardiac surgery (1.09 [1.04–1.12]), VATS (0.95 [0.90–1.00]), and hip replacement (0.55 [0.52–0.57]) compared with patients undergoing laparoscopic cholecystectomy (hazard ratio=1). Results from propensity score matched analyses and sensitivity analyses were similar. Conclusions: The risk of postoperative depression differs by surgical type after controlling for preoperative characteristics.