Cost of Illness (COI)

Cost of Illness (COI) studies quantitatively assess the total economic burden of a specific disease on society, encapsulating both direct and indirect costs. Direct costs include all healthcare-related expenses such as diagnostics, treatments, and ongoing disease management, along with patients’ personal expenditures, which might cover items like travel to medical facilities and over-the-counter medications. Indirect costs generally reflect productivity losses incurred from reduced work capacity or time off due to illness.

These studies meticulously compile and analyze data from various sources, such as healthcare surveys and patient registries, applying standardized ‘unit costs’ to resource use figures to estimate the overall economic impact across affected population groups. In the U.S., COI studies might convert service charges to actual costs using established cost-to-charge ratios, providing a comprehensive picture of the financial demands imposed by the disease.

While COI studies are invaluable for illustrating the extensive economic impacts and disparities associated with certain diseases, they do not function as economic evaluations per se. They do not predict cost variations that could result from the adoption of new medical treatments or interventions. Instead, they serve to establish a baseline from which the economic effects of potential health interventions can be measured. Costs ‘attributable’ to a disease are often assessed by comparing expenses between matched groups with and without the disease, though this approach can be complex in cases where individuals may suffer from multiple coexisting conditions (e.g., obesity and diabetes), potentially leading to an overestimation of costs attributable to any single condition.

Overall, COI studies highlight the significant financial strain that diseases can place on individuals and society, underlining the importance of effective health interventions that could alleviate these costs. Such studies are crucial for policymakers and health care providers as they plan resource allocation and strategize on broader health system improvements.