The cross-sectional and longitudinal association of the BODE index with quality of life in patients with chronic obstructive pulmonary disease.
BACKGROUND
The body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index was shown at predicting the risk of death, exacerbation and disease severity among patients with COPD, but few studies verified relationship between BODE index and health related quality of life (HRQoL) among Chinese COPD patients. The objective of this study was to evaluate the relationship between BODE index and HRQoL in cross-sectional and longitudinal association analyses.


METHODS
A multi-center prospective cohort study was initially conducted in 491 stable COPD patients in Beijing, China. Health status (HRQoL) was assessed by St. George's Respiratory Questionnaire (SGRQ); the BODE index was calculated for each patient; dyspnea was assessed using the 5-grade Medical Research Council dyspnea scale. Other measurements included socio-demographic, body mass index (BMI), lung function test and 6-minute-walk test (6MWT). Patients were then followed monthly for 12 months.


RESULTS
Only 450 patients completed the 1-year follow up and were enrolled in our present analyses. Mean age was (65.2 +/- 10.6) years, men 309 (68.7%). The BODE index was categorized into 4 subgroups: 0 - 2, 3 - 4, 5 - 6 and 7 - 10. At baseline BODE index was gradually increased with baseline total SGRQ and SGRQ subscales (P trend < 0.001). For individual components of BODE index, with the decrease of airflow limitation, and 6MWD, and with the increase of Medical Research Council (MRC) dyspnea grade, total SGRQ and SGRQ subscales were increased correspondingly, P trend < 0.05, respectively. Similar association patterns were found between baseline BODE index and its individual components and mean SGRQ scores at the end of 1-year follow up. By multiple linear regression analyses, baseline BODE index was not only significantly associated with SGRQ score at baseline but also with SGRQ score at the end of 1-year follow up after adjustment for age, male, current smoking, betas being 0.434 and 0.378, respectively.


CONCLUSIONS
BODE index is associated with SGRQ score cross-sectionally and longitudinally among stable COPD patients. BODE index might have potential to be used as a sensitive tool to assess the status of quality of life and to monitor disease progression among stable COPD patients.
Lin
Ying-Xiang
YX
Beijing Institute of Respiratory Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China.
Xu
Wan-Ning
WN
Liang
Li-Rong
LR
Pang
Bao-Sen
BS
Nie
Xiu-Hong
XH
Zhang
Jie
J
Wang
Hong
H
Liu
Yu-Xiang
YX
Wang
Dan-Qi
DQ
Xu
Zhen-Yang
ZY
Wang
Hong-Wu
HW
Zhang
Hu-Sheng
HS
He
Zheng-Yi
ZY
Yang
Ting
T
Wang
Chen
C
D000368:Aged; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D004417:Dyspnea / Q000473:pathology / Q000503:physiopathology; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000473:pathology* / Q000503:physiopathology*; D011788:Quality of Life; D012129:Respiratory Function Tests; D012907:Smoking; D011795:Surveys and Questionnaires