Seminars

General Departmental Seminar Series

An Splus Package to Adjust for Reporting Delay of PRCA Cases

Zhilong Yuan, Graduate Student
Department of Statistics, University of Wisconsin-Madison

Friday, November 7, 2003, 12-1 p.m.

K6/115 Clinical Science Center, 600 Highland Ave.

ABSTRACT

This talk is about my work as a summer intern at Johnson & Johnson Pharmaceutical Research and Development(PRD).

EPREX is used worldwidely to treat anemia for Chronic Renal Failure(CRF) and Cancer patients. However, recent postmarketing data have indicated a loss of effect(LOE), possibly related to Pure Red Cell Aplasia(PRCA), among some CRF patients. The disease is rare but very severe, and is the major reason of the slump of the sale of the drug. The company now publishs monthly reports about the disease, and the incidence rates are calculated based on the reported cases. This tends to underestimate recent occurrence because of the right-truncated nature of the data from reporting delay. Adjustment is performed by estimating the proportion of cases reported by the database lock date using Product-limit estimate or Cox Proportional Hazards models. A SPLUS package is developed to implement the adjustment as well as produce various graphs for the monthly reports. Graphic User Interface(GUI) and on-line documentation are also provided. The July data is used to perform an example analysis.

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