• Which incidence or prevalence rate to use.
• Which health effects and associated care and services to include. For instance, what medical conditions are to be treated and what percentage of affected persons have each particular condition? Is lost productivity to be estimated? Are indirect costs, such as administrative, policy, and research costs, to be included? Are nonworkforce morbidity costs to be included?
• Adjustments for the difference in the value of current dollars versus dollars that will be needed years in the future.

In addition, when examining the cost of an illness or condition, it is important to understand the limitations of the estimates. These estimates do not:

• Estimate the amount of money or years of life that can be saved by effective social policies and programs, since estimates include both avoidable and unavoidable costs.
• Show the budgetary impact of the illness or condition on governments, but rather on all of society.
• Seek to consider the economic benefits of prevention.