Modified BODE indexes: Agreement between multidimensional prognostic systems based on oxygen uptake.
OBJECTIVE
It has been recently shown that the original BODE index has a high degree of correlation with two modified BODE indexes using maximal oxygen uptake expressed either as mL/min/kg (mBODE) or as the percentage predicted (mBODE%). In this study we investigated the agreement between the two modified BODE indexes (mBODE and mBODE%) in patients with stable chronic obstructive pulmonary disease (COPD).


METHODS
A total of 169 patients with stable COPD were enrolled in this cross-sectional study. Differences between the two mBODE indexes were assessed using kappa coefficients and Bland-Altman plots. One out of every three patients underwent the six-minute walking test to investigate the agreement with the original BODE index.


RESULTS
Correlations between the two mBODE indexes with each other (r = 0.96, P < 0.001) and with the original BODE index (mBODE r = 0.88, P < 0.001; mBODE% r = 0.93, P < 0.001) were excellent. However, the two mBODE indexes were significantly different from each other (mBODE 5.27 +/- 2.3 versus mBODE% 4.31 +/- 2.5; P < 0.001). The kappa coefficients were significantly lower (entire study group k = 0.5, P < 0.001) for every GOLD stage. The mean difference between the two mBODE indexes was 0.8 +/- 0.6 units. Differences with the original BODE were higher for the mBODE (1.8 +/- 0.9) than for the mBODE% (0.6 +/- 0.8).


CONCLUSIONS
The new mBODE indexes are highly correlated but significantly different from each other. The differences between the novel indexes deserve further scrutiny.
Lopez-Campos
José Luis
JL
Hospitales Universitarios Virgen del Rocío, Seville, Spain. lcampos@separ.es <lcampos@separ.es>
Cejudo
Pilar
P
Marquez
Eduardo
E
Ortega
Francisco
F
Quintana
Esther
E
Carmona
Carmen
C
Barrot
Emilia
E
D000368:Aged; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019370:Observation; D010101:Oxygen Consumption / Q000502:physiology*; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012720:Severity of Illness Index; D013030:Spain; D016138:Walking
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