A Frailty Model for Crossing-Hazard Data

• 발행기관: 한국자료분석학회
• 저자명: 하일도(Il Do Ha)
• 간행물 정보: 『Journal of The Korean Data Analysis Society (JKDAS)』Vol.10 No.1, 11~18쪽, 전체 8쪽
• 주제분류: 자연과학 > 통계학
• 파일형태: PDF
• 발행일자: 2008.02.28

영문 초록

The crossing hazards are often observed in clinical trials on time-to-event. This indicates a strong non-proportional hazards (non-PH) structure and may occur due to a heterogeneity between survival data. Frailty, a random-effect term in hazard models, usually accounts such heterogeneity and the resulting marginal model, which is obtained by integrating out the frailty, leads to a non-PH model. Accordingly, in this paper we propose how to model the crossing hazards via a frailty and to fit the proposed model using SAS PROC NLMIXED. The proposed method is illustrated with a well-known data set from a randomized clinical trial on gastric cancer patients, where the aim of trial is to investigate the effect of chemotherapy (group 1) and combined chemotherapy and radiotherapy (group 2) on survival times of gastric cancer patients.

목차

1. Introduction

2. Example

3. The proposed method

4. Illustration

5. Discussion

References

키워드

Crossing hazards Frailty models Non-proportional hazards Weibull models