Advances in networking and small sensors (motes, RFID tags, etc) have made it possible to monitor and provide medical assistance to people in need at their homes. Recently, WISP tags, one advanced technology of Radio Frequency Identification (RFID) tags, have been used to monitor indoor activity, vital signs, sleep quality, and health status remotely. These types of systems take collaborative decision based on the data collected from all the WISP tags of the system. Any missing tag data within the environment may introduce critical error in the system's decision and this eventually may jeopardize system's decision reliability. In order to maintain system's reliability, a monitoring protocol needs to be executed frequently and it should be made efficient in terms of execution time. This paper studies the problem of monitoring a large set of WISP tags and identifying the missing ones. In this paper, based on probabilistic methods, we propose a monitoring protocol for WISP based Smart Healthcare Monitoring Systems. The goal of this protocol is to improve the security and reliability of a smart healthcare monitoring system by detecting missing tags and reporting back only the data of the existing tags.