Health-related quality of life is associated with COPD severity: a comparison between the GOLD staging and the BODE index

Abstract

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease. Currently, severity Global initiative for chronic Obstructive Lung Disease (GOLD) criteria are used to diagnose the severity of COPD, but a new grading system, the body mass index, bronchial obstruction, dyspnea, exercise (BODE) index, was recently proposed to provide useful prognostic information. The objective of this study is to evaluate the association between health-related quality of life (HRQOL) and COPD severity assessed by two criteria: the GOLD classification and the BODE index. Sixty-four patients with COPD were examined with lung function tests and specific and generic HRQOL questionnaires (St. George's Respiratory Questionnaire [SGRQ], Nottingham Health Profile [NHP]). Participants were divided into four severity groups using the GOLD guidelines and the BODE index quartiles. The association between NHP and SGRQ subscales, and the BODE index was significant (P < 0.01). However, the GOLD classification shows a correlation only with SGRQ total score (P < 0.05) but not with NHP or SGRQ subscales. There was an association of the SGRQ total score between the severity groups of BODE (P = 0.0001), but there was no difference in the SGRQ total score between the severity groups of GOLD classification (P = 0.244). The present study suggests that COPD severity assessed by the BODE index can be more directly related with HRQOL.