Health economics of chronic obstructive pulmonary disease.

Studies describing the economic impact of chronic obstructive pulmonary disease (COPD) are used for several purposes. There can, however, be limitations as costs based on results of a clinical trial are likely to be significantly different from real world practice. Sometimes, it may be more useful to capture the costs of the important components accurately rather than the often unachievable aim of capturing every cost however small. Burden of illness studies can help identify clinical targets or patterns of care-for example, hospitalization-that are major health care cost drivers. In the United Kingdom, burden of COPD studies suggest an annual cost of 781 pounds sterlings- 1,154 pounds sterlings per patient. Cost analyses can be divided into four types: cost minimization, cost-effectiveness, cost benefit, and cost utility. Utilities such as quality-adjusted life year (QALY) measure the effectiveness of different therapies, and can be obtained in various ways and in different populations, potentially leading to significant differences in the results. Payers often apply cost per QALY thresholds when assessing whether a new therapy should be used or not. In the United Kingdom, it is accepted that there is a sigmoid relationship between the cost per QALY and the likelihood of a therapy being recommended, with a lower inflection between 5,000 pounds sterlings and 15,000 sterlings, below which rejection is unlikely and an upper inflection between 25,000 pounds sterlings and 35,000, above which acceptance is unlikely, but not impossible. On this basis, pulmonary rehabilitation and inhaled steroids are unlikely to be rejected but lung volume reduction surgery may be.