Club drug use was highly prevalent in the NYC afterhours nightclub scene in the early 2000s. We assessed 450 gay and bisexual men four times over a year (in the early 2000s) about their club drug use. We surveyed about use of the following five drugs: crystal meth, ecstasy, ketamine, GHB and cocaine. Below are the means of use of each drug for the men in this sample who reported use at Time 1 and at Time 2 (Month 12). We want to know whether level of use ("number of days used in the previous four months") changed over time (for each of the five drugs). We hypothesize that use changed over time, but we aren't sure about specific direction. So we are interested in whether there are changes in use of each of the five drugs between the two time points, separately. Paired Samples Statistics Mean Sid. Deviation Std. Error Mean crystal 1 3.05 93 8,642 896 Pair 1 crystal 12 10.10 93 14.356 1.489 ecstasy1 5.11 253 7.651 481 Pair 2 ecstasy12 2.47 253 6.301 396 ketamine 1 11.43 58 10.277 Pair 3 1.349 ketamine12 3.29 58 14.566 1.913 ghb1 10.63 16 17.161 4.290 Pair 4 ghb12 4.88 16 7.060 1.765 coke 1 21.95 162 25. 165 1.977 Pair 5 coke12 15.31 162 20.593 1.618 Paired Samples Test Paired Differences df Sig. (2- Mean Sid Std. Error 95% Confidence Interval of tailed) Deviation Mean the Difference Lower Upper Pair 1 crystal1 - crystal12 -1.043 15.141 1.570 -4.161 2.075 664 Pair 2 ecstasy1 - ecstasy12 92 508 2.636 8.077 .508 636 3.636 5.192 252 Pair 3 ketamine1 - ketamine12 000 3.138 15.897 2.08 -1.042 7.318 1.603 57 Pair 4 ghb1 - ghb12 138 5.750 11.958 2.99 -622 12 122 1.923 15 X 5 coke1 - coke12 074 6.636 26.543 2.08 2.517 10.75 3.182 161 002 Question 4 (1 point) Use of what drug(s) significantly increased or decreased over time? All drugs Cocaine and ecstasy Cocaine, ecstasy and ketamine Ketamine and crystal meth Question 5 (1 point) Ketamine use _ _ over time stayed the same significantly increased significantly decreased decreased, but not significantly