The influence of various graphical and numeric trend display formats on the detection of simulated changes.

Integration of a large amount of information is important in anaesthesia but there is little research to guide the development of data displays. Anaesthetists from two hospitals participated in five related screen based simulation studies comparing various formats for display of historical or 'trend' data. Participants were asked to indicate when they first noticed a change in each displayed variable. Accuracy and latency (i.e. delay) in detection of changes were recorded. Latency was shorter with a graphic display of historical data than with a numeric display. Increasing number of variables or reduction of y-axis height increased the latency of detection. If the same number of data points were included, there was no difference between graphical and numerical displays of historical data. There was no difference in accuracy between graphical or numerical displays. These results suggest that the way trend data is presented can influence the speed of detection of changes.