COPD and biomarkers: the search goes on

almost all be similarly categorised using the LLN or other criteria. The differences that we would find relate to the mild category. In the BOLD study, GOLD stage 1 was not included in the overall estimates, 9 although others have shown that people in this category have increased morbidity and mortality. 10 11 While mild disease may be more ''treatable'' it may also be part of the spectrum of ''normal''. It may also be true that early evidence of disease may be more important as an indicator of non-respiratory disease, such as cardiovascular disease. Furthermore, in mild to moderate disease the recommended interventions are based on treating symptoms, whereas in severe to very severe disease they are based on both treating symptoms and preventing exacerbations.