Accuracy of caring personnel in estimating water intake based on missing liquid in drinking vessels

In this contribution a measurement regarding estimations of filling levels in drinking vessels is presented. Ensuring a sufficient hydration is an important task in nursing homes. Monitoring of fluid intake is normally achieved by visual examination of drinking vessels conducted by staff members. This contribution describes a measurement targeted at evaluating this method in order to analyze the requirements of technical aids. Data gained by conducting this measurement in a cooperating elderly people home is presented and analyzed. Key results are that residents drink on average 5 to 10 percent less than it is recorded and that estimations of especially partly filled vessels vary strongly. Both, the type of drinking vessel and the current filling level influence the accuracy and precision of the difference between estimation and actual missing liquid.