Although some carers live with the elders, they have to go to work during the day and do not spend much time with them every day, while the security guards, neighbors, relatives and friends are the ones who receive the elders the most every day. They are in the best position to understand whether the elders are unable to cope with their daily needs due to deterioration in their cognitive ability, such as answering questions, going out with all the keys in their hand, pressing the buttons correctly on the lifts, searching for their own homes, and recognizing the way, and so on. If caregivers can establish a tacit understanding with them in advance and maintain close communication with them, they will be able to contact the caregivers once they notice any abnormality, which will help to locate the lost elders as soon as possible.
