Nonparametric estimation of hazard rates change-point

위험률의 변화점에 대한 비모수적 추정

  • 정광모 ((609-735) 부산시 금정구 장전동 산30, 부산대학교 통계학과)
  • Published : 1998.03.01

Abstract

The change of hazard rates at some unknown time point has been the interest of many statisticians. But it was restricted to the constant hazard rates which correspond to the exponential distribution. In this paper we generalize the change-point model in which any specific functional forms of hazard rates are net assumed. The assumed model includes various types of changes before and after the unknown time point. The Nelson estimator of cumulative hazard function is introduced. We estimate the change-point maximizing slope changes of Nelson estimator. Consistency and asymptotic distribution of bootstrap estimator are obtained using the martingale theory. Through a Monte Carlo study we check the performance of the proposed method. We also explain the proposed method using the Stanford Heart Transplant Data set.

위험률 변화점모형에서 특별한 함수형이나 분포함수에 대한 가정을 하지 않는 일반적인 모형을 고려하였다. 이러한 모형은 지금까지 주로 다루어 왔던 상수항 위험률의 변화점모형뿐만 아니라 여러 유형의 변화점모형을 내포한다. 중도절단된 자료하에서 위험률 변화점에 관한 모수적 모형을 가정하지 않고 변화점 이전과 이후의 넬슨(Nelson) 누적위험함수 추정량의 기울기 차를 이용하여 추정량을 제안하고, 그의 점근적 성질을 규명한다. 붓스트랩 추정량의 일치성과 점근분포를 유도하고, 몇가지 분포함수의 경우에 몬테칼로 모의실험을 통해 제안된 방법의 경험적 성질을 살펴보았다. 또한, 심장병 이석환자의 생존시간 자료를 통해 변화점을 추정하고 추정량의 붓스트랩 분포를 구하였다.

Keywords

References

  1. The Annals of Statistics v.6 no.4 Nonparametric Inference for a Family of Counting Processes Aalen, O.
  2. Journal of the American Statistical Association v.81 no.396 Bootstrapping the Kaplan-Meier Estimator Akritas, M.G.
  3. Annals of Mathematical Statistics v.39 Nonparametric Tests for Shift at Unknown Time Point Bhattacharyya, G. K.;Johnson, R. A.
  4. The Annals of Statistics v.16 no.1 Nonparametric Change-Point Estimation Carlstein, E.
  5. Lecture Notes 23 Estimation in Change-Point Hazard Rate Models With Random Censorship, Change-Point Problems Chang, I.S.;Chen, C. H.;Hsiung, C. A.
  6. Annals of Mathematical Statistics v.35 Estimating the Current Mean of a Normal Distribution Which is Subject to Changes in Time Chernoff, H.;Zacks, S.
  7. Analysis of Survival Data Cox, D. R.;Oakes, D.
  8. The Annals of Statistics v.19 no.3 The Asymptotic Behaviour of Some Nonparametric Change-Point Estimators Dumbgen, L.
  9. Journal of the American Statistical Association v.76 Censored Data and the Bootstrap Efron, B.
  10. Introduction to the Bootstrap Efron, B.;Tibshirani, R. J.
  11. Biometrika v.57 Inference for a Hazard Rate Change-Point in a Sequence of Random Variables Hinkley, D. V.
  12. Biometrika v.78 Inference for a Hazard Rate Change Point Loader, C. R.
  13. Biometrika v.71 Estimation in Change-Point Hazard Rate Models Nguyen, H. T.;Rogers, G. S.;Walker, E. A.
  14. Biometrika v.41 Continuous Inspection Schemes Page, E. S.
  15. Applied Statistics v.28 A Non-parametric Approach to the Change-Point Problem Pettitt, A. N.
  16. Biometrika v.68 Estimating the MedianSurvival Time Reid, N.
  17. Communications in Statistics-Theory and Methods v.15 no.8 Maximum Likelihood Estimation in Hazard Rate Models with a Change-Point Yao, Yi-Ching