Media type: E-Article Title: Authors' reply Contributor: Tu, Yu‐Kang; Gilthorpe, Mark S. imprint: Wiley, 2007 Published in: Statistics in Medicine Language: English DOI: 10.1002/sim.2722 ISSN: 0277-6715; 1097-0258 Keywords: Statistics and Probability ; Epidemiology Origination: Footnote: