Analysis of Dependently Truncated Sample Using Inverse Probability Weighted Estimator
نویسندگان
چکیده
Many statistical methods for truncated data rely on the assumption that the failure and truncation time are independent, which can be unrealistic in applications. The study cohorts obtained from bone marrow transplant (BMT) registry data are commonly recognized as truncated samples, the time-to-failure is truncated by the transplant time. There are clinical evidences that a longer transplant waiting time is a worse prognosis of survivorship. Therefore, it is reasonable to assume the dependence between transplant and failure time. To better analyze BMT registry data, we utilize a Cox analysis in which the transplant time is both a truncation variable and a predictor of the time-to-failure. An inverse-probability-weighted (IPW) estimator is proposed to estimate the distribution of transplant time. Usefulness of the IPW approach is demonstrated through a simulation study and a real application. INDEX WORDS: Left truncation, Dependent, Inverse probability weighting, Cox regression model, SAS programming ANALYSIS OF DEPENDENTLY TRUNCATED SAMPLE USING INVERSE PROBABILITY WEIGHTED ESTIMATOR
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