title: The combined association of depression and socioeconomic status with length of post-operative hospital stay following coronary artery bypass graft surgery: data from a prospective cohort study.
abstract: OBJECTIVE
  To understand the association between pre-operative depression symptoms, including cognitive and somatic symptom subtypes, and length of post-operative stay in patients undergoing coronary artery bypass graft (CABG) surgery, and the role of socioeconomic status (SES).
  
  
  METHODS
  We measured depression symptoms using the Beck Depression Inventory (BDI) and household income in the month prior to surgery in 310 participants undergoing elective, first-time, CABG. Participants were followed-up post-operatively to assess the length of their hospital stay.
  
  
  RESULTS
  We showed that greater pre-operative depression symptoms on the BDI were associated with a longer hospital stay (hazard ratio=0.978, 95% CI 0.957-0.999, p=.043) even after controlling for covariates, with the effect being observed for cognitive symptoms of depression but not somatic symptoms. Lower SES augmented the negative effect of depression on length of stay.
  
  
  CONCLUSIONS
  Depression symptoms interact with socioeconomic position to affect recovery following cardiac surgery and further work is needed in order to understand the pathways of this association.
authors.affiliation: Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, UK. Electronic address: lydia.poole.09@ucl.ac.uk.
authors.forename: Lydia
authors.initials: L
authors.lastname: Poole
authors.affiliation: Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Leigh
authors.affiliation: Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, UK.
authors.forename: Tara
authors.initials: T
authors.lastname: Kidd
authors.affiliation: Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, UK.
authors.forename: Amy
authors.initials: A
authors.lastname: Ronaldson
authors.affiliation: Department of Cardiac Surgery, St George's Hospital, University of London, Blackshaw Road, London, UK.
authors.forename: Marjan
authors.initials: M
authors.lastname: Jahangiri
authors.affiliation: Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Steptoe
mesh_terms: D000368:Aged; D001026:Coronary Artery Bypass; D003863:Depression / Q000523:psychology; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012923:Social Class
keywords: ACS; ARCS study; Adjustment and Recovery after Cardiac Surgery study; BDI; BMI; Beck Depression Inventory; CABG; CI; Coronary artery bypass graft surgery; Depression; EuroSCORE; European System for Cardiac Operative Risk Evaluation; HADS; Hospital Anxiety and Depression Scale; Income; Length of stay; Recovery; Socioeconomic position; acute coronary syndrome; body mass index; confidence intervals; coronary artery bypass graft