Modification of a Motor-Response Dependent Measure of Daytime Sleepiness (OSLER-2)

Background: A simple, portable measure of daytime sleepiness is the Oxford Sleep Resistance (OSLER-2) test; however its use is limited to those with good hand function. This study modified the OSLER-2 test to assess the measurement of daytime sleepiness using two alternative, non-hand-held response switches. Methods: The unit was modified to accept the standard hand-held switch, a head-tap switch (“Jelly-bean”) and chin-tap switch (“Wand”). Participants were required to respond to a central LED light presented for one second every three seconds. It terminated following either seven consecutive missed responses (participant asleep) or forty minutes (maximum test length, “performance time”). Twenty-two able-bodied participants with no diagnosed sleep disorders were sleep restricted prior to three testing days where switch order was randomized. The test was performed four times over each day. Sleep latency, performance times and errors were recorded along with video of the switch use. Results: Sleep latency was longer with the Wand (M=1265 sec (546)) than the Jelly-bean (M=1102 (544)) and hand-held switch (M=1037 sec (557), p<0.05). Performance times were longer with the Wand (M=1788 sec (695)) than the Jelly-bean (M=1530 sec (758); p<0.05) and hand-held switch (M=1459 sec (784); p<0.01). Sleep latency, performance times and errors did not differ significantly between the Jelly-bean and hand-held switches. Video suggested the Wand was occasionally activated erroneously by forward (drowsy) head-drops. Conclusion: The Jelly-bean provides a possible alternative response switch to measure daytime sleepiness in those with limited hand function.