Prognostic Indices and Mortality Prediction in COPD Caused by Biomass Smoke Exposure

Little is known about survival and prognostic factors in chronic obstructive pulmonary disease (COPD) due to biomass smoke exposure (BS-COPD).

(1) To determine the value of two indices of COPD severity: BODEx (body mass index, obstruction, dyspnea, and previous severe exacerbations) and Global Initiative for Chronic Obstructive Lung Disease (GOLD) categories system (ABCD) to predict all-cause mortality in BS-COPD, compared with COPD due to tobacco (T-COPD); (2) to verify the usefulness of 2 comorbidity indices, Charlson index and COTE (COPD comorbidity index); and (3) to put side by side the value of these indices.

612 consecutive COPD patients were retrospectively studied. Prognostic factors were evaluated taking into account the exposure to biomass or tobacco smoke. The relative predictive values of the prognostic indices were compared using receiver-operating characteristic analysis.

Mortality in the BS-COPD and T-COPD groups was not significantly different, when sex was taken into account. BODEx, Charlson and COTE indices-but not type of exposure-predicted mortality in multivariate analysis. The value of the C-statistic for the BODEx index was not different than that of GOLD ABCD for BS-COPD, but was higher for T-COPD. The discriminatory value of the Charlson index was higher than that of COTE for BS-COPD, but no significant differences were found for T-COPD.

Multidimensional indices of COPD severity and comorbidity predict all-cause mortality in BS-COPD. The behavior of the different indices is different for BS-COPD and T-COPD.