Int. J. Environ. Res. Public Health 2011, 8 1676 Table 1. Cont. Characteristic Overall (n = 4,988) CA (n = 1,245) US (n = 1,130) UK (n = 1,263) AU (n = 1,350) Income Low 1,516 (32.5) 315 (27.1) 385 (35.7) 413 (35.6) 403 (31.7) Moderate 1,677 (35.9) 455 (39.1) 405 (37.6) 404 (34.8) 413 (32.5) High 1,478 (31.6) 393 (33.8) 288 (26.7) 343 (29.6) 454 (35.7) Education Low 2,595 (52.0) 557 (44.8) 472 (41.8) 743 (59.4) 823 (61.0) Moderate 1,543 (31.0) 463 (37.2) 432 (38.3) 334 (26.7) 314 (23.3) High 832 (16.7) 223 (17.9) 224 (19.9) 173 (13.8) 212 (15.7) SES High 1,182 (25.4) 349 (30.0) 279 (27.6) 254 (22.1) 282 (22.2) Moderate 2,495 (53.6) 626 (53.9) 572 (53.1) 594 (51.7) 703 (55.4) Low 980 (21.0) 187 (16.1) 208 (19.3) 301 (26.2) 284 (22.4) CPD mean (SD) 17.29 (10.0) 16.25 (9.1) 18.55 (10.8) 16.34 (9.4) 18.10 (10.4) Minutes to 1st cig mean (SD) 66.62 (135.6) 58.66 (121.7) 58.23 (121.7) 68.74 (131.9) 78.99 (159.3) HSI mean (SD) 2.69 (1.54) 2.7 (1.51) 2.82 (1.57) 2.53 (1.45) 2.73 (1.61) Smoking Status (W5) Daily 4,725 (94.7) 1,179 (94.7) 1,079 (95.5) 1,203 (95.2) 1,264 (93.6) Weekly 211 (4.2) 50 (4.0) 42 (3.7) 53 (4.2) 66 (4.9) Monthly 52 (1.0) 16 (1.3) 9 (0.8) 7 (0.6) 20 (1.5) Smoking Status (W6) Current 4,456 (89.3) 1,129 (90.7) 1,020 (90.3) 1,103 (87.3) 1,204 (89.2) Quit 532 (10.7) 116 (9.3) 110 (9.7) 160 (12.1) 146 (10.8) All by country comparisons are statistically significant at p < 0.05 level based on chi square analyses. CPD = Cigarettes per day (baseline). SD = Standard Deviation. HSI = Heaviness of Smoking Index (baseline); composite measure of CPD and Minutes to 1st cigarette after waking, range from 0 to 6 with 6 being more addicted. In all subsequent models, only HSI will be added into the model with values ranging from 1 to 6. A second set of longitudinal analyses encompasses the time period from October, 2006 until July, 2009 and utilizes waves 5, 6, and 7 of the ITC-4 study. This analysis was completed among 3,387 respondents who were smokers at waves 5 and 6 and were followed through to wave 7. Demographic characteristics in this sub-population were similar to those in the wave 5-wave 6 longitudinal cohort. 2.3. Definition of Purchasing Behaviors Identification of last purchase from a low or untaxed venue was determined from each respondents‘ last reported purchase location. Responses were categorized as follows: (1) Convenience store, gas station, newsstand; (2) Grocery store, discount/‖big box‖ outlet stores; (3) Discount tobacco outlet venues or tobacco specialty shops; (4) entertainment venues such as bars, restaurants, casinos; (5) liquor stores; (6) from a vending machine; (7) Military commissaries; (8) Duty-free shops; (9) Indian Reservations; (10) Outside the state/country of residence; (11) by Internet or telephone; or