Longitudinal change in the BODE index predicts mortality in severe emphysema.
BACKGROUND
The predictive value of longitudinal change in BODE (Body mass index, airflow Obstruction, Dyspnea, and Exercise capacity) index has received limited attention. We hypothesized that decrease in a modified BODE (mBODE) would predict survival in National Emphysema Treatment Trial (NETT) patients.


OBJECTIVE
To determine how the mBODE score changes in patients with lung volume reduction surgery versus medical therapy and correlations with survival.


METHODS
Clinical data were recorded using standardized instruments. The mBODE was calculated and patient-specific mBODE trajectories during 6, 12, and 24 months of follow-up were estimated using separate regressions for each patient. Patients were classified as having decreasing, stable, increasing, or missing mBODE based on their absolute change from baseline. The predictive ability of mBODE change on survival was assessed using multivariate Cox regression models. The index of concordance was used to directly compare the predictive ability of mBODE and its separate components.


RESULTS
The entire cohort (610 treated medically and 608 treated surgically) was characterized by severe airflow obstruction, moderate breathlessness, and increased mBODE at baseline. A wide distribution of change in mBODE was seen at follow-up. An increase in mBODE of more than 1 point was associated with increased mortality in surgically and medically treated patients. Surgically treated patients were less likely to experience death or an increase greater than 1 in mBODE. Indices of concordance showed that mBODE change predicted survival better than its separate components.


CONCLUSIONS
The mBODE demonstrates short- and intermediate-term responsiveness to intervention in severe chronic obstructive pulmonary disease. Increase in mBODE of more than 1 point from baseline to 6, 12, and 24 months of follow-up was predictive of subsequent mortality. Change in mBODE may prove a good surrogate measure of survival in therapeutic trials in severe chronic obstructive pulmonary disease. Clinical trial registered with www.clinicaltrials.gov (NCT 00000606).
Division of Pulmonary and Critical Care Medicine, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0360, USA. fmartine@umich.edu
Fernando J
FJ
Martinez
Meilan K
MK
Han
Adin-Cristian
AC
Andrei
Robert
R
Wise
Susan
S
Murray
Jeffrey L
JL
Curtis
Alice
A
Sternberg
Gerard
G
Criner
Steven E
SE
Gay
John
J
Reilly
Barry
B
Make
Andrew L
AL
Ries
Frank
F
Sciurba
Gail
G
Weinmann
Zab
Z
Mosenifar
Malcolm
M
DeCamp
Alfred P
AP
Fishman
Bartolome R
BR
Celli
D000368:Aged; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D011013:Pneumonectomy; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000401:mortality / Q000628:therapy; D011656:Pulmonary Emphysema / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D016032:Randomized Controlled Trials as Topic; D012720:Severity of Illness Index; D015996:Survival Rate; D014481:United States / Q000453:epidemiology