Additionally , those who received the intervention were less likely to have reported driving within 6 hours after taking hydrocodone ( usual care 13.6 % , 95 % CI = 7.2 % to 20 % vs. intervention 3 % , 95 % CI = -0.3 % to 6.3 % ; difference = 10.6 , 95 % CI of difference = 3.4 to 17.9 ) .