Table 1.
Description of Baseline Characteristicsa of the Study Population, Overall and by Smoking Cessation Status, the Coronary Artery Risk Development in Young Adults (CARDIA) Study, 1985–2001, N = 1489 Baseline Daily Smokers
| Overall | Quit smoking (first cessation)b | No first cessation | p valuec | Quit smoking (sustained cessation)b | No sustained cessation | p valuec | |
|---|---|---|---|---|---|---|---|
| N | 1489 | 875 | 614 | 432 | 1057 | ||
| Baseline age, mean (SD), years | 25.0 (3.6) | 25.2 (3.5) | 24.8 (3.8) | <.0001 | 25.1 (3.5) | 25.0 (3.7) | .05 |
| Gender, N (%) | .01 | .02 | |||||
| Male | 730 (49.0) | 405 (46.3) | 325 (52.9) | 192 (44.4) | 538 (50.9) | ||
| Female | 759 (51.0) | 470 (53.7) | 289 (47.1) | 240 (55.6) | 519 (49.1) | ||
| Race, N (%) | <.0001 | <.0001 | |||||
| Black | 862 (57.9) | 467 (53.4) | 395 (64.3) | 206 (47.7) | 656 (62.1) | ||
| White | 627 (42.1) | 408 (46.6) | 219 (35.7) | 226 (52.3) | 401 (37.9) | ||
| Maximum education, mean (SD) yearsd | 13.8 (2.3) | 14.3 (2.4) | 13.0 (2.0) | <.0001 | 14.5 (2.5) | 13.5 (2.2) | <.0001 |
| Household income, mean (SD), per $10 000)e | 4.3 (2.8) | 4.7 (2.9) | 3.6 (2.4) | <.0001 | 5.2 (2.9) | 3.9 (2.7) | <.0001 |
| Married/living as married, N (%) | 287 (19.3) | 172 (19.7) | 115 (18.7) | .7 | 82 (19.0) | 205 (19.4) | .9 |
| Alcohol use in past year, N (%) | 1394 (93.6) | 814 (93.0) | 580 (94.5) | .3 | 409 (94.7) | 985 (93.2) | .3 |
| Total physical activity, mean (SD)f | 404.9 (293.2) | 412.1 (301.0) | 394.7 (281.4) | .0003 | 397.2 (272.3) | 408.1 (301.3) | .03 |
| Body mass index, mean (SD), kg/m2 | 24.5 (5.1) | 24.6 (5.0) | 24.3 (5.2) | .0004 | 24.4 (4.6) | 24.5 (5.3) | .2 |
| Smoking-related health condition at baseline, N (%)g | 312 (21.0) | 189 (21.6) | 123 (20.0) | .5 | 94 (21.8) | 218 (20.6) | .6 |
| Workplace smoking ban (self-reported) N (%)h | 212 (14.2) | 156 (17.8) | 56 (9.1) | <.0001 | 79 (18.3) | 133 (12.6) | .004 |
aCharacteristics presented are from the initial examination (1985–1986) unless otherwise noted.
bOutcomes included first cessation and sustained cessation. “Quit smoking (first cessation)” indicates a participant who was a current smoker at baseline and reported being a nonsmoker/smoking zero cigarettes per day at a follow-up examination or annual telephone contact, regardless of whether or not they later relapsed. “Quit smoking (sustained cessation)” indicates a participant who reported a first cessation and then reported being a nonsmoker/smoking zero cigarettes per day at all subsequent follow-up examinations or annual telephone contacts (cessation with no relapse).
c p values are from chi-squared tests for categorical variables and t tests for continuous variables.
dEducation was reported in every year. These values reflect maximum educational attainment over the follow-up period.
eIncome was first reported in year 5. These values reflect the average income over follow-up (years 5–15), adjusted for inflation to 2000 US dollars.
fPhysical activity was measured in self-reported exercise units that accounted for the frequency and intensity of each activity.
gIncluding asthma, hypertension, cancer, heart disease, or diabetes. This variable was constructed to adjust for health conditions that might influence participants to quit smoking.
hIn year 5. Self-reported workplace smoking policy was not recorded in year 0.