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Complete Prevalence

Complete Prevalence represents the proportion of people alive on a certain day who were diagnosed with the disease, regardless of how long ago the diagnosis was made. Complete prevalence can be estimated from self-reported population-based surveys (Byrne et al., 1992), although one must be concerned with underreporting and misclassification of disease. Direct computation (the counting method) of complete cancer prevalence requires registry data that has been collected over a sufficiently long period of time to capture all prevalent cases of the disease.

In the United States, the only registry with sufficient incidence and follow-up data to approximate complete cancer prevalence is the Connecticut Tumor Registry (Connelly et al., 1968; Gershman et al., 1976). The Connecticut registry has information on cancer cases from as early as 1935, although computations do not usually include cases diagnosed prior to 1940. However, projecting estimates of US prevalence from Connecticut is not optimal because Connecticut is less representative of the United States than SEER. Moreover, from SEER, prevalence can be estimated by race and ethnicity. The completeness index (Capocaccia & De Angelis, 1997; Merrill et al., 2000), a statistical model to estimate complete prevalence from limited-duration prevalence, has been derived and used to estimate complete prevalence from SEER limited-duration prevalence, survival, and incidence data (see Chapter 29 of the SEER Cancer Statistics Review, 1973-1999External Web Site Policy for a description of the methods).

Complete prevalence statistics can be calculated using the ComPrev software.