title: A longitudinal study of serial BODE indices in predicting mortality and readmissions for COPD.
abstract: BACKGROUND
  BODE index comprises Body mass index, Obstruction of the airway [FEV(1)], Dyspnoea score [modified Medical Research Council questionnaire] and Exercise capacity [6 min walk test]. This study assessed the role of serial changes in BODE index in predicting mortality and readmissions of COPD patients.
  
  
  METHODS
  A prospective cohort study involving 243(208 males) COPD patients hospitalized for acute exacerbations of COPD [AECOPD]. BODE index was assessed at 6 weeks(baseline), 6, 12, 18 and 24 months post hospital discharge. Mortality and readmissions in the subsequent 3 years were recorded. All the patients were managed by usual care without additional intervention.
  
  
  RESULTS
  The mean (SD) age and FEV(1)% predicted were 74.2(7.8) yrs and 51.7(21.6)% respectively. Over the 3 years, 25.1% died whereas 76.5% had at least 1 readmission for AECOPD. Baseline BODE index was predictive of both the survival and readmissions to hospital for AECOPD by Cox regression analysis (p < 0.001 for both survival and readmissions). Over 24 months, 71(40.1%), 94(53.1%), 12(6.8%) patients had increased (>1 point), no change, and decreased in BODE (>1 point) index respectively. Serial changes in BODE index at 6 month was marginally associated with mortality, but not at 12-, 18- and 24-month. The 6-, 12- and 24-month BODE indices were predictive of the readmissions for AECOPD when compared to baseline.
  
  
  CONCLUSIONS
  Baseline BODE index could predict both survival and readmissions for AECOPD, whereas serial BODE indices were not predictive of survival at 3 years. Single rather than serial measurements of BODE index is sufficient for prediction of survival and readmissions for patients treated with usual care.
authors.affiliation: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong.
authors.forename: Fanny W S
authors.initials: FW
authors.lastname: Ko
authors.forename: Wilson
authors.initials: W
authors.lastname: Tam
authors.forename: Alvin H M
authors.initials: AH
authors.lastname: Tung
authors.forename: Jenny
authors.initials: J
authors.lastname: Ngai
authors.forename: Susanna S S
authors.initials: SS
authors.lastname: Ng
authors.forename: Kenneth
authors.initials: K
authors.lastname: Lai
authors.forename: Ka-Fai
authors.initials: KF
authors.lastname: Au
authors.forename: David S C
authors.initials: DS
authors.lastname: Hui
mesh_terms: D000368:Aged; D015992:Body Mass Index; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010359:Patient Readmission / Q000191:economics / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology; D012720:Severity of Illness Index