Improved Kaplan-Meier Estimator in Survival Analysis Based on Partially Rank-Ordered Set Samples

Abstract EN

This study presents a novel methodology to investigate the nonparametric estimation of a survival probability under random censoring time using the ranked observations from a Partially Rank-Ordered Set (PROS) sampling design and employs it in a hematological disorder study.

The PROS sampling design has numerous applications in medicine, social sciences and ecology where the exact measurement of the sampling units is costly; however, sampling units can be ordered by using judgment ranking or available concomitant information.

The general estimation methods are not directly applicable to the case where samples are from rank-based sampling designs, because the sampling units do not meet the identically distributed assumption.

We derive asymptotic distribution of a Kaplan-Meier (KM) estimator under PROS sampling design.

Finally, we compare the performance of the suggested estimators via several simulation studies and apply the proposed methods to a real data set.

The results show that the proposed estimator under rank-based sampling designs outperforms its counterpart in a simple random sample (SRS).