1. Global Initiative for Chronic Obstructive Lung Disease (GOLD): Global strategy for the diagnosis, management and prevention of chronic obstructive pulmonary disease NHLBI/WHO workshop report. In Publication Number 2701. National Institutes of Health, National Heart Lung and Blood Institute; 2001.
2. Seemungal TA, Donaldson GC, Paul EA, Bestall JC, Jeffries DJ, Wedzicha JA: Effect of exacerbation on quality of life in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1998, 157:1418–1422.
3. Wildman M, Groves J, Walia S, Stableforth D, Ayres J: Hospitalised COPD exacerbations: survival and univariate outcome predictors, 36-month follow-up [abstract]. Am J Respir Crit Care Med 2002,165(2 pt 2):A272.
4. Niederman MS, McCombs JS, Unger AN, Kumar A, Popovian R: Treatment cost of acute exacerbations of chronic bronchitis. Clin Ther 1999, 21:576–591.
5. Murray C, Lopez A: Alternative projections of mortality and disability by cause 1990–2020: global burden of disease study. Lancet 1997, 349:1498–1504.