There is little consensus on the best way to measure emergency department (ED) crowding. We have previously developed a consensus-based measure, the International Crowding Measure in Emergency Departments. We aimed to externally validate a short form of the International Crowding Measure in Emergency Department (sICMED) against emergency physician’s perceptions of crowding and danger.
We performed an observational validation study in seven EDs in five different countries. We recorded sICMED observations and the most senior available emergency physician’s perceptions of crowding and danger at the same time. We performed a times series regression model.
A total of 397 measurements were analysed. The sICMED showed moderate positive correlations with emergency physician’s perceptions of crowding, r = 0.4110, P < 0.05) and safety (r = 0.4566, P < 0.05). There was considerable variation in the performance of the sICMED between different EDs. The sICMED was only slightly better than measuring occupancy or ED boarding time.
The sICMED has moderate face validity at predicting clinician’s concerns about crowding and safety, but the strength of this validity varies between different EDs and different countries.