Bed-exit alarm effectiveness

Abstract

This study describes the accuracy of two types of bed-exit alarms to detect bed-exiting body movements: pressure-sensitive and a pressure-sensitive combined with infrared (IR) beam detectors (dual sensor system). We also evaluated the occurrence of nuisance alarms, or alarms that are activated when a participant does not attempt to get out of bed. Fourteen nursing home residents were directly observed for a total of 256 nights or 1636.5h; an average of 18.3+/-22.3 (+/-S.D.) nights/participant for an average of 6.4+/-1.2 h/night. After adjusting for body movements via repeated measures, Poisson regression modeling, the least squares adjusted means (LSM) show a marginally significant difference between the type of alarm groups on the number of true positives (NTP) (mean/S.E.M.=0.086/1.617) for pressure-sensitive versus dual sensor alarm (0.593/1.238; p=0.0599) indicating that the dual sensor alarm may have a higher NTP. While the dual sensor bed-exit alarm was more accurate than the pressure-sensitive alarm in identifying bed-exiting body movements and reducing the incidence of false alarms, false alarms were not eliminated altogether. Alarms are not a substitute for staff; adequate staff availability is still necessary when residents need or wish to exit bed.