Pragmatic research and outcomes in asthma and COPD

Abstract

Asthma and chronic obstructive pulmonary disease (COPD) are common diseases which cause patients and society considerable difficulties. These are costly diseases which cause substantial morbidity and death. Health care policy makers have made improving outcomes in asthma and COPD a priority. Application of guideline recommended approaches to asthma and COPD care in the real-life setting has been emphasized but outcomes have not improved. Failure to improve outcomes may not be because of inconsistent applications of guideline recommendations, but rather because there are difficulties implementing the Expert Panel Report III (EPR 3) method for categorizing asthma severity and the Global Initiative for Obstructive Lung Disease (GOLD) method for diagnosing COPD. As these serve as the foundation for treatment recommendations for these diseases, alternative approaches should be considered for categorizing asthma severity and identifying COPD patients. Claims-based algorithms provide an intriguing option for identifying persistent asthma patients and symptomatic COPD patients in administrative databases. These methods could be used as the basis for pragmatic research, both retrospective and prospective, on assessing outcomes of guideline recommended treatment approaches in asthma and COPD. Important questions urgently need to be answered about how guideline recommended approaches regarding use of long-acting inhaled β-agonist/inhaled corticosteroid (LABA/ICS) in asthma and long-acting inhaled anti-muscarinic agent (LAMA) and LABA/ICS in COPD affect outcomes in real-life situations.

Keywords: asthma; chronic obstructive pulmonary disease; pragmatic research.

Figure 1

The EPR 3 recommended approach to asthma severity categorization for asthma patients 12 years of age and older is complex. Notes: Just below the title is the reminder, often not considered, that this severity categorization method should only be applied to patients not currently taking long-term controllers. The categorization method includes two domains. The impairment domain includes five variables which are both subjective and objective. The risk domain includes exacerbations. The worst ranking in any individual impairment and risk domain determines overall severity. Abbreviation: EPR 3, Expert Panel Report III.

Figure 2

(A) A normal bronchial biopsy from a patient without asthma compared with (B) a bronchial biopsy specimen from a patient with a history of asthma but in complete remission demonstrates epithelial shedding and extensive presence of α-major basic protein. Note: Both of these findings indicate active ongoing airway inflammation. Reprinted with permission of the American Thoracic Society. Copyright © 2012 American Thoracic Society. LM Van den Toorn, SE Overbeek, JC de Jongste, K Leman, HC Hoogsteden, JB Prins/2001/Airway inflammation is present during clinical remission of atopic asthma/American Journal of Respiratory Critical Care Medicine/164/2107–2103. Official Journal of American Thoracic Society.

Figure 3

(A) Cumulative severe exacerbations were significantly reduced when asthma treatment was determined by induced sputum eosinophilia used in conjunction with guideline methods (sputum management group) than guideline methods alone (BTS management group). (B) The cumulative incidence of mild first exacerbations was significantly lower when asthma therapy was adjusted based on methacholine testing used along with guideline methods (AHR-strategy) than guideline methods alone (Reference-strategy). Note: 3B is reprinted from Lancet, Vol 360, Issue 9347, Ruth H Green, Christopher E Brightling, Susan McKenna, Beverley Hargadon, Debbie Parker, Peter Bradding, Andrew J Wardlaw, Ian D Pavord, Asthma exacerbations and sputum eosinophil counts, Pages 1715–1721, Copyright 2002, with permission from Elsevier. Abbreviations: AHR, airway hyperresponsiveness; BTS, British Thoracic Society.

Figure 4

The horizontal red line indicates the fixed FEV₁/FVC ratio of 0.70. The black circles above this line represent patients without COPD. The predicted normal post-bronchodilator FEV₁/FVC ratio decreases with age. The black diagonal line represents the age-adjusted lower limit of normal for the FEV₁/FVC for men. The green circles below this line represent patients with COPD. The red circles between the two lines indicate the 558 (16% of the entire cohort of 3473 men studied) symptomatic male current and ex-smokers referred for spirometry testing who would have been incorrectly diagnosed with COPD based on using the fixed threshold rather than the predicted lower limit of normal. Note: Reproduced from Robberts B, Schermer T. Abandoning FEV₁/FVC < 0.70 to detect airway obstruction. Chest. 2011;139(5):1253–1254 with permission of the publisher. Abbreviations: COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in one second; FVC, forced vital capacity.

Figure 5

As COPD severity stage increases, the frequency of exacerbations requiring hospitalization increases. The percent of patients with frequent exacerbations (ie, two or more exacerbations per year) also increased with COPD severity stage. In GOLD Stage 2 COPD the exacerbation rates were 0.85 per year. The high exacerbation rate suggests that an algorithm based on claims for COPD exacerbations could be a useful approach to identifying COPD patients in GOLD Stage 2 and above. Note: Reproduced from Price DB, Tinkelman DG, Halbert RJ, et al. Symptom-based questionnaire for identifying COPD in smokers. Respiration. 2006;73(3):285–295 with permission of the publisher. Copyright New England Journal of Medicine. Abbreviations: COPD, chronic obstructive pulmonary disease; GOLD, Global Initiative for Obstructive Lung Disease.