title: Correcting for lead time and length bias in estimating the effect of screen detection on cancer survival.
abstract: Determination of survival time among persons with screen-detected cancer is subject to lead time and length biases. The authors propose a simple correction for lead time, assuming an exponential distribution of the preclinical screen-detectable period. Assuming two latent categories of tumors, one of which is more prone to screen detection and correspondingly less prone to death from the cancer in question, the authors have developed a strategy of sensitivity analysis for various magnitudes of length bias. Here they demonstrate these methods using a series of 25,962 breast cancer cases (1988-2004) from the West Midlands, United Kingdom.
authors.affiliation: Cancer Research UK Centre for Epidemiology, Mathematics and Statistics, Wolfson Institute for Preventive Medicine, London, United Kingdom.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Duffy
authors.forename: Iris D
authors.initials: ID
authors.lastname: Nagtegaal
authors.forename: Matthew
authors.initials: M
authors.lastname: Wallis
authors.forename: Fay H
authors.initials: FH
authors.lastname: Cafferty
authors.forename: Nehmat
authors.initials: N
authors.lastname: Houssami
authors.forename: Jane
authors.initials: J
authors.lastname: Warwick
authors.forename: Prue C
authors.initials: PC
authors.lastname: Allgood
authors.forename: Olive
authors.initials: O
authors.lastname: Kearins
authors.forename: Nancy
authors.initials: N
authors.lastname: Tappenden
authors.forename: Emma
authors.initials: E
authors.lastname: O'Sullivan
authors.forename: Gill
authors.initials: G
authors.lastname: Lawrence
mesh_terms: D000368:Aged; D015982:Bias; D001943:Breast Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008403:Mass Screening; D008875:Middle Aged; D015233:Models, Statistical; D012680:Sensitivity and Specificity; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology