Abstract
The present article discusses the characterization of non negative integer-valued random variable using reversed variance residual life. A special attention is given to the characterizations by relationship between conditional variance and the reversed failure rate. A lower bound to the conditional variance is also established. Our bound is compared to the Cramer-Rao and Chapman-Robbins lower bounds so that construction of minimum variance unbiased estimators of relevant parametric functions in truncated distributions can be possible.