Discriminative and predictive properties of multidimensional prognostic indices of chronic obstructive pulmonary disease: A validation study in Taiwanese patients

Background and objective Chronic obstructive pulmonary disease (COPD) is a pulmonary disease with systemic involvement. Several multidimensional indices have been developed to predict long-term outcomes. However, these indices have not been compared and validated in Taiwanese patients with COPD. Methods A prospective, observational, hospital-based study was designed, and a total of 621 patients were recruited from May 2006 to December 2011. Patients followed at least 1 year were enrolled and 594 patients eligible for inclusion. Three prognostic indices - the ADO (age, dyspnoea and airflow obstruction), BODEx (body mass index, airflow obstruction, dyspnoea and exacerbations), and CPI (the COPD Prognostic Index) - were validated and the predictive power of each was analysed. Results The median follow-up of the 594 patients was 33 months (range 1-72 months), and the mortality rate was 19.2% (114 deaths). All indices were significantly predictive for all-cause mortality in our validation cohort. Furthermore, the C statistics of the three indices, indicating their predictive accuracy, were all >0.7 (area under the curve of the CPI 0.718, P < 0.001, ADO 0.702, P < 0.001, BODEx 0.702, P < 0.001). Conclusions ADO, BODEx and CPI scores are useful predictors of all-cause mortality with significantly discriminative properties in Taiwanese patients with COPD. We demonstrate that the ADO, BODEx and CPI scores could act as useful predictors of all-cause mortality with significantly discriminative properties in Taiwanese patients with COPD.