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Activity Number:
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548
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Type:
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Contributed
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Date/Time:
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Thursday, August 2, 2007 : 10:30 AM to 12:20 PM
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Sponsor:
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Section on Statistics in Epidemiology
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| Abstract - #308991 |
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Title:
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Length-Biased Sampling in Cancer Screening with Variable Test Sensitivity
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Author(s):
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Sonya Heltshe*+ and Karen Kafadar
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Companies:
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University of Colorado at Denver and Health Services Center and University of Colorado at Denver and Health Services Center
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Address:
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800 W 12th Ave, Denver, CO, 80204,
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Keywords:
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randomized screening trial ; test sensitivity ; length-bias ; sojourn time ; cancer
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Abstract:
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Length biased sampling exists in screening programs where disease may be detected during the preclinical stage, since a longer sojourn time yields a greater likelihood of being screen-detected (Zelen 1976). This paper quantifies the effect of length-biased sampling on clinical duration when cases are subject to periodic screening with variable test sensitivity. Screening test sensitivity as a function of age and sojourn time, underlying bivariate distribution, correlation (between sojourn and clinical time), mixing proportion of slow versus fast progressing disease, and the ratio of screening interval length to mean sojourn time all influence the magnitude of the effect that length-biased sampling has on the distribution of clinical duration.
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