Phenotyping of obstructive airways disease

<p>Background Asthma and Chronic Obstructive Pulmonary Disease (COPD) are heterogeneous disorders which may be made up of different sub-types, or phenotypes, of airflow obstruction with distinct clinical characteristics. To facilitate personalised treatment the different phenotypes and their response to treatment must be clearly defined and sound diagnostic rules developed. In this thesis I explore the evidence supporting candidate phenotypes and report the results of my research, known as the New Zealand Respiratory Health Survey (NZRHS). The NZRHS was designed to determine candidate phenotypes, compare these phenotypes to those previously described, characterize their response to inhaled medication, and develop a method for allocating patients to the most appropriate phenotype. Research Aims -To explore clinical phenotypes of chronic airways disease by cluster analysis. -To examine if phenotypes identified by a previous cluster analysis exist in the independent NZRHS sample. -To compare the response to a short-acting beta-agonist inhaler between phenotype groups. -To compare the response to a short-acting muscarinic antagonist inhaler between phenotype groups. -To compare the response to an inhaled corticosteroid between phenotype groups. -To generate allocation rules and determine their predictive value for the different disorders of airways disease. Conclusions This research has identified phenotypes of airways disease that differ significantly in their clinical and pathophysiological characteristics. Evidence is presented to support the existence of the asthma/COPD overlap and obesity/co-morbid phenotypes and provide data of their responsiveness to inhaled corticosteroid, beta agonist and anti-muscarinic treatments, which may guide future management of patients with these phenotypes of obstructive airways disease.</p>