Naslov
Specificity of diagnostic test has potentially large effect on disease frequency measures in community-based studies

Autori
Rudan, Igor

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Proceedings of the World Health Organization Meetings on Global Burden of Disease / Black, Robert ; Bryce, Jennifer - Ženeva : WHO, 2003

Skup
World Health Organization Meetings on Global Burden of Disease

Mjesto i datum
Ženeva, Švicarska, 12.02.2003. - 16.02.2003

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
screening test; diagnosis; disease frequency measures; community-based studies

Sažetak
In epidemiological studies where the major aim is to measure burden of disease in a community, especially in developing countries, episodes of disease will be identified by a chosen diagnostic test. However, measures of disease frequency (e.g. prevalence and incidence) reported in those studies will not represent the actual number of persons with disease in a community, but rather the number of persons who tested positive. Those two values may be very similar, but may also be very far apart, depending on the properties of the diagnostic test applied. We propose the "TAP ratio" (ratio of Test to Actual Positives, which is ideally 100%) as the most useful summary measure of the utility of the test to accurately estimate disease frequency. In this paper, we use a range of examples to demonstrate how improving test sensitivity and specificity can not only fail to bring "TAP ratio" closer to 100%, but also further decrease the accuracy of disease frequency estimates. However, by understanding the relationship between sensitivity and specificity of diagnostic test and the true prevalence of studied disease in a population, any test can be configured appropriately to provide very accurate estimates. The optimal test characteristics for use in a population-based survey are likely to be different to those when the test is utilised in a clinical setting. In observational (burden of disease) studies, configuring "TAP ratio" to close to 100% will yield accurate disease frequency estimates, and in intervention studies it will prevent inaccurate calculation of the power of the trial to detect differences between study groups. We present these relationships algebraically and graphically to illustrate how, under realistic scenarios of disease prevalence, sensitivity of the applied diagnostic test represents principal determinant of the "TAP ratio" measure.

Izvorni jezik
Engleski

Znanstvena područja
Javno zdravstvo i zdravstvena zaštita

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