Fig. 2From: Crowding in the emergency department in the absence of boarding – a transition regression model to predict departures and waiting timeDiagnostics: Residuals against fitted values and QQ-plots of residual and theoretical quantiles. Stratified on shift and weekday/weekend. Residuals against fitted values plot: Linearity indicated by a symmetric distribution around zero with no trend. Homoscedasticity indicated by no trend in the vertical scatter. Independent errors indicated by lack of any pattern. QQ-plot: To check for normalityBack to article page