Table 4

The trip and consumptions

Variables1996
N=2197
2011
N=3558
Standardisation*p Value
Number of changes of driver since de beginning of the tripNS
 Mean±SD0.19±0.600.23±0.610.27
Stops since the beginning of the trip<0.0001
 Mean±SD2.70±1.642.16±1.262.31
Total duration of stops<0.0001
 Mean±SD174±38461±14478.5
Sleep during stops%<0.0001
 No1744 (86.9)3358 (94.4)93.2
 Yes263 (13.1)200 (5.6)6.8
Sleeping as a passenger%NS
 No1898 (94.6)3384 (95.1)93.8
 Yes108 (5.4)174 (4.9)6.2
Number of cans of caffeinated drink/cups of coffee or tea per day<0.0001
 Mean±SD2.8 (2.4)3.5 (2.8)3.6
Do you use sleeping pills at least once a week?NS
 Yes92 (4.6)164 (4.6)3.5
 No1915 (95.4)3394 (95.4)96.5
Do you use awakening medications at least once a week?<0.01
 Yes27 (1.4)13 (0.4)0.4
 No1980 (98.6)3545 (99.6)99.6
Did you use awakening medications during this trip?<0.01
 Yes20 (1.0)10 (0.3)0.2
 No1987 (99.0)3548 (99.7)99.8
Do you smoke<0.0001
 Yes674 (33.6)781 (22.0)22.0
 Non1333 (66.4)2777 (78.0)78.0
  • *Standardisation: The standardisation column represents the rate and average that will be found if the 2011 drivers had the same distribution than the 1996 population according to age, sex and driving distance.