CALCULATION OF THE COST OF ASTHMA BY SEVERITY AND DEGREE OF CONTROL

The asthmatic population was grouped, on the basis of clinicians' estimates¹⁵ into five severity categories (very mild, mild, moderate, severe and very severe) according to the extent to which underlying symptoms of the disease are exhibited. These symptoms included reduced lung function and impairment of lifestyle due to asthma. The majority (over 80%) of diagnosed adult asthmatics are either very mild or mild, about 10% are moderate and around 6% are severe or very severe asthmatics (See Figure One).

Leading clinicians were also surveyed to determine the relative proportions of well controlled and poorly controlled asthmatics within each of the severity classifications. These estimates were used as a basis for allocating cost elements across the severity groups; on the whole, poorly controlled asthmatics place a greater cost burden on society than well controlled ones. Clinicians' estimates of the demands of each asthma severity group on the health system were reconciled with actual utilisation data for each medical cost category to develop the medical cost per asthmatic within each of the five classifications.

¹⁵ 297 GPs were contacted (66 GPs replied) via a postal questionnaire with results giving a severity category statistical confidence interval of 99%. 27 respiratory specialists throughout Australia were interviewed.

Content Updated 1992