%0 Journal Article %A Dipansu Ghosh %A Samantha L. Jamson %A Paul D. Baxter %A Mark W. Elliott %T Effect of time on test on driving simulator performance in patients with obstructive sleep apnoea (OSAS) %D 2011 %J European Respiratory Journal %P p1739 %V 38 %N Suppl 55 %X Introduction: A sophisticated office based driving simulator (MiniSim) is being developed to assess driving performance in OSAS. We have shown in a credible way that a failure on the simulator can be accurately predicted from continuously recorded variables. We have now explored the way these variables change over time.Methods: After a practice run, 72 patients (Age 53±10,ESS 12±6,ODI 39±21) & 17 controls completed 50 minutes motorway driving (7 epochs) on the MiniSim. Two situations were programmed that required evasive action to avoid a crash; minor & major events. A “fail” was defined by an unprovoked crash or crash at the minor event. A crash at the major event was deemed as “indeterminate”, the rest were deemed to have “passed”. Continuous driving parameters including High Frequency Steering (HFS) and lane position (SDLP) for these three categories were plotted against time & data from the controls were added to the plot.Results: Performance worsens with time in all patients with OSAS but the progression is worse in the subgroup who fail the simulator test.They also perform worse than others from the beginning (p<0.0001 in epoch 1).Conclusion: These data suggest that patients who will crash during simulated driving can be identified early in the run, which has implications for the duration of the test. Furthermore the consistency of the abnormalities suggests that these are not chance phenomena. %U