View PDF Version - RePub - Erasmus Universiteit Rotterdam
View PDF Version - RePub - Erasmus Universiteit Rotterdam
View PDF Version - RePub - Erasmus Universiteit Rotterdam
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Chapter 3.1<br />
138<br />
U i = Time to failure (HCC) for subject i if never exposed to glycyrrhizin (=counterfactual<br />
failure time)<br />
Glycyrrhizini (t) = The treatment status of subject i at timepoint t.<br />
The model that relates the observed data Ti and Glycyrrhizini (Ti) to the counterfactual<br />
failure time Ui is assumed to be:<br />
Ti Ui (ψ) = ∫ exp (ψ Glycyrrhizini (t)) dt<br />
0<br />
The model of U as a function of ψ describes the relation between the counterfactual<br />
failure time, the observed failure time and the use of glycyrrhizin over time.<br />
Acknowledgements<br />
The following Japanese investigators contributed to the study by sharing individual<br />
patient data:<br />
N. Izumi1 , J. Toyota2 , T. Aikawa3 , S. Fujiyama4 , K. Yasuda5 , A. Shibuya6 , Y. Hirose7 , H.<br />
Harada8 , S. Hige9 , G. Yamada10 , E. Tanaka11 , N. Ohno12 .<br />
1Musashino Red Cross Hospital, Tokyo; 2Sapporo Kousei General Hospital, Hokkaido;<br />
3Aikawa Internal Hospital, Ibaraki; 4Kumamoto University Hospital, Kumamoto; 5Kiyo kawa Hospital, Tokyo; 6Kitasato University East Hospital, Kanagawa; 7Yamanashi Central<br />
Prefectural Hospital, Yamanashi; 8National Tokyo Hospital, Tokyo; 9Hokkaido University<br />
School of Medicine, Hokkaido; 10Kawasaki Medical School, Okayama; 11Shinsu University<br />
School of Medicine, Nagano; 12Ohno Internal & Gastroenterology Clinic, Ehime.<br />
We thank mr. N. Yamamoto for his important contribution in the data collection.<br />
We thank the following experts for their highly valuable advice on study design and<br />
statistical methods: 1M.A. Hernán, T. Poynard2 , T. Stijnen3 , S. Iino4 and N. Hayashi5 .<br />
1 Department of Epidemiology, School of Public Health, Harvard University, Boston MA,<br />
USA. 2Service d’Hépato- Gastroenterologie, Groupe Hospitalier Pitié Salpétrière, Paris,<br />
France. 3Department of Epidemiology and Biostatistics, <strong>Erasmus</strong> Medical Center <strong>Rotterdam</strong>,<br />
<strong>Rotterdam</strong>, The Netherlands. 4Department of Medicine, St. Marianna University<br />
School of Medicine, Kawasaki, Kanagawa, Japan. 5Department of Gastroenterology and<br />
Hepatology, Osaka University Hospital, Osaka, Japan.<br />
This study was supported by an unrestricted grant from Minophagen Pharmaceutical Co<br />
Ltd., Japan.