title: Role of BMI, airflow obstruction, St George's Respiratory Questionnaire and age index in prognostication of Asian COPD.
abstract: COPD is a complex condition with a heavy burden of disease. Many multidimensional tools have been studied for their prognostic utility but none has been universally adopted as each has its own limitations. We hypothesize that a multidimensional tool examining four domains, health-related quality of life, disease severity, systemic effects of disease and patient factors, would better categorize and prognosticate these patients.
  
  
  
  We first evaluated 300 patients and found four factors that predicted mortality: BMI, airflow obstruction, St George's Respiratory Questionnaire and age (BOSA). A 10-point index (BOSA index) was constructed and prospectively validated in a cohort of 772 patients with all-cause mortality as the primary outcome. Patients were categorized into their respective BOSA quartile group based on their BOSA score. Multivariate survival analyses and receiver operator characteristic (ROC) curves were used to assess the BOSA index.
  
  
  
  Patients in BOSA Group 4 were at higher risk of death compared with their counterparts in Group 1 (hazard ratio (HR): 0.29, 95% CI: 0.16-0.51, P < 0.001) and Group 2 (HR: 0.53, 95% CI: 0.34-0.82, P = 0.005). Race and gender did not affect mortality. The area under the ROC curve for BOSA index was 0.690 ± 0.025 while that for Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 was 0.641 ± 0.025 (P = 0.17).
  
  
  
  The BOSA index predicts mortality well and it has at least similar prognostic utility as GOLD 2011 in Asian patients. The BOSA index is a simple tool that does not require complex equipment or testing. It has the potential to be used widely.
authors: Division of Respiratory and Critical Care Medicine, University Medicine Cluster, National University Health System, Singapore.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Hiang Ping
authors: HP
authors: Chan
authors: Division of Respiratory and Critical Care Medicine, University Medicine Cluster, National University Health System, Singapore.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Amartya
authors: A
authors: Mukhopadhyay
authors: Division of Respiratory and Critical Care Medicine, University Medicine Cluster, National University Health System, Singapore.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Pauline Lee Poh
authors: PL
authors: Chong
authors: Division of Respiratory and Critical Care Medicine, University Medicine Cluster, National University Health System, Singapore.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Sally
authors: S
authors: Chin
authors: Division of Respiratory and Critical Care Medicine, University Medicine Cluster, National University Health System, Singapore.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Xue Yun
authors: XY
authors: Wong
authors: Division of Respiratory and Critical Care Medicine, University Medicine Cluster, National University Health System, Singapore.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Venetia
authors: V
authors: Ong
authors: Biostatistics Unit, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Yiong Huak
authors: YH
authors: Chan
authors: Division of Respiratory and Critical Care Medicine, University Medicine Cluster, National University Health System, Singapore.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Tow Keang
authors: TK
authors: Lim
authors: Division of Respiratory and Critical Care Medicine, University Medicine Cluster, National University Health System, Singapore.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Jason
authors: J
authors: Phua
mesh_terms: D000368:Aged; D044466:Asian People; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000208:ethnology / Q000503:physiopathology / Q000523:psychology; D011788:Quality of Life; D012372:ROC Curve; D012846:Singapore / Q000453:epidemiology; D011795:Surveys and Questionnaires
keywords: chronic obstructive pulmonary disease; classification; morbidity; mortality; prognosis