Monitoring disease progression in COPD patients: one step beyond!

Chronic obstructive pulmonary disease (COPD) is defined by persistent airflow limitation that is usually progressive [1], and its severity has long been classified using forced expiratory volume in 1 s (FEV1) % predicted. Although levels of FEV1 were often reported to predict mortality, the observation that other pulmonary and extrapulmonary variables also predicted mortality led to the development of various multidimensional indices to predict survival in COPD [2]. The BODE index, which comprises nutritional status assessed by body mass index (BMI), airflow obstruction (FEV1 % pred), dyspnoea (using the modified Medical Research Council (mMRC) scale) and exercise capacity (6-min walking distance (6MWD)), was developed 10 years ago as a predictor of all-cause and respiratory mortality [3]. The BODE index has been externally validated in many settings and remains one of the best multidimensional tools for predicting mortality in COPD patients [2]. Surprisingly, very little data are available on longitudinal evolution of the BODE index in cohorts of COPD patients.