COPD is a costly disease. These are words we hear all the time, yet the precise meaning of this phrase is a bit nebulous, and peeking behind the curtain to determine how this is actually measured and evaluated reveals more questions and problems. What are the definitions and approaches to determining these costs?1
• Direct medical costs: hospital inpatient payments, physician payments, prescription drugs, medical supplies and devices, nursing home care, and so forth.
• Indirect medical costs: premature death, absenteeism, loss of resources, and so forth. There are multiple methods to determining these “costs,” such as the “human capital method” (lost earnings of a patient or caregiver) or the “willingness to pay method” (eg, how much would you be willing to pay to avoid an ED visit?).1
• Top-down approach: measures the proportion of a disease related to exposure to the disease or risk factor, and uses aggregated data along with a population-attributable fraction to estimate costs.
• Bottom-up approach: estimates costs by calculating the average cost of treatment of the illness and multiplying it by the prevalence of the illness.
• Econometric approach: estimates the difference in costs between a cohort of the population with the disease and a cohort of the population without the disease. Regression analysis is used to adjust for polymorbidity.