Health Challenges, Latin America
sick but do not know it. Although that that last phrase may seem an oxymoron, people who do not know their health status or the risks to it constitute potentially a major source of unmet need.
This can arise for an early and asymptomatic stage of a disease,
particularly a chronic condition such as diabetes or cardiovascular disease; or a current risk factor such as smoking, obesity or exposure to toxic substances or pollution. For cases of incipient or early-stage disease, starting treatment earlier may be more costeffective than when the disease is more advanced. DCP2 includes estimates of the costs and results of early detection for HIV infection that has not yet progressed to AIDS (chapter 18), several kinds of cancer (chapter 20), diabetes (chapter 30), hemoglobinopathies (chapter 34) and dental caries (chapter 38). There are no estimates of the number of people who do not realize they already have one of these conditions, but two approaches show that unrecognized illness is important as an explanation for inadequate utilization of care. Detecting those cases when the patient is unaware of his or her condition through screening will vary greatly in cost-effectiveness depending on the prevalence of the condition, the target population, the frequency of screening or testing and the cost of treating the previously undiagnosed cases. Table 2 reports the expected results of various cervical cancer screening programs in Brazil. Either of the two less expensive approaches could avert one death for every 100 women screened, while adding less than US$ 5.00 to lifetime costs per woman, compared to no screening and later treatment of cases. The table also illustrates the waste, in lives and money, that results from choosing the least cost-effective program. A modeling exercise in Australia (Walker and Colaguiri 2007) looks at screening for diabetes, or high risk of the disease, among those aged 45+ with risk factors, and all
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