title: The relationship of the BODE index to oxygen saturation during daily activities in patients with chronic obstructive pulmonary disease.
abstract: BACKGROUND
  The frequency of oxygen desaturation during daily activities in chronic obstructive pulmonary disease (COPD) is poorly defined. The BODE index predicts survival in COPD. The purpose of this study was to determine the relationship between BODE scores and oxygen saturation during daily activities.
  
  
  METHODS
  Seventy-eight patients with COPD (FEV(1) = 37%) underwent ambulatory oximetry and activity monitoring. We defined four activity categories: Walking, Slow-Intermittent-Walking (SIW), Active-Not-Walking (ANW), and Rest. We quantified oxygen desaturation during activity using a desaturation index (DSI = % time oxygen saturation <90%). BODE scores were categorized into three groups: group I (0-3), II (4-6), and III (7-10).
  
  
  RESULTS
  The percentage of patients demonstrating oxygen desaturation (DSI ≥ 10%) during each activity was 55% for Walking, 35% for SIW, 15% for ANW, and 28% for Rest. There was a strong association between BODE score and desaturation for Walking and SIW. During Walking, 21, 44, and 86% of patients in BODE groups I, II, and III, respectively, demonstrated desaturation. The DSI for Walking and SIW was increased in patients in BODE groups II and III compared to group I (P < 0.006, P < 0.007, respectively). BODE score was also linked to long-term oxygen therapy (LTOT) usage; the majority of patients not on LTOT (89%) had a BODE score <7. The majority of patients on LTOT (84%) demonstrated desaturation during Walking, but 42% of patients not on LTOT also demonstrated desaturation. In this subgroup of patients not on LTOT, all patients with a BODE score ≥ 7 demonstrated desaturation during Walking.
  
  
  CONCLUSIONS
  The link between the BODE index and oxygen desaturation during daily activities suggests that desaturation is linked to disease severity. Our data suggest that patients with a BODE score ≥ 7 should be evaluated for desaturation during daily activities. Use of the BODE index to screen for exertional desaturation may have value as a tool that can lead to the earlier identification of patients who may be candidates for LTOT.
authors.affiliation: Pulmonary and Critical Care Section, Department of Medicine, Veteran's Administration Medical Center, SUNY/Downstate Health Sciences Center, 800 Poly Place, Brooklyn, NY 11209, USA. michael.cutaia@va.gov
authors.forename: Michael
authors.initials: M
authors.lastname: Cutaia
authors.forename: Robin
authors.initials: R
authors.lastname: Brehm
authors.forename: Miriam
authors.initials: M
authors.lastname: Cohen
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D015331:Cohort Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010100:Oxygen / Q000097:blood* / Q000627:therapeutic use; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality / Q000503:physiopathology*; D012720:Severity of Illness Index; D016138:Walking / Q000502:physiology
chemical_list: D010100:Oxygen