Between-wave smoking initiation* in the COMPASS follow-up (2014/15) longitudinal sample, Ontario and Alberta, Canada (n = 17 318)
| Characteristic (at baseline) | No. (%) within category who initiated smoking by follow-up | OR (95% CI) | |
|---|---|---|---|
| Unadjusted† | Adjusted‡ | ||
| Age, yr | |||
| ≤ 14 | 436/5936 (7.3) | 1.0 (ref) | 1.0 (ref) |
| 15 | 511/5845 (8.7) | 1.23 (1.07–1.41) | 1.08 (0.94–1.25) |
| 16 | 397/4464 (8.9) | 1.27 (1.10–1.47) | 1.04 (0.89–1.21) |
| ≥ 17§ | 105/1073 (9.8) | 1.43 (1.13–1.79) | 1.02 (0.80–1.32) |
| Sex | |||
| Female | 683/9289 (7.4) | 1.0 (ref) | 1.0 (ref) |
| Male | 766/8029 (9.5) | 1.37 (1.22–1.52) | 1.44 (1.28–1.62) |
| Race/ethnicity¶ | |||
| White | 1143/13 423 (8.5) | 1.0 (ref) | 1.0 (ref) |
| Black | 42/562 (7.5) | 1.00 (0.72–1.40) | 1.03 (0.72–1.45) |
| Asian | 44/925 (4.8) | 0.62 (0.45–0.85) | 0.67 (0.72–0.93) |
| Aboriginal | 58/328 (17.7) | 2.04 (1.50–2.77) | 1.29 (0.93–1.80) |
| Latin American/Hispanic | 21/274 (7.7) | 0.98 (0.62–1.54) | 0.71 (0.44–1.15) |
| Other/mixed | 140/1735 (8.1) | 1.00 (0.83–1.20) | 0.95 (0.78–1.16) |
| Spending money, $ | |||
| 0 | 224/3342 (6.7) | 1.0 (ref) | 1.0 (ref) |
| 1–20 | 454/6048 (7.5) | 1.14 (0.96–1.34) | 1.00 (0.84–1.20) |
| 21–100 | 416/4077 (10.2) | 1.57 (1.32–1.86) | 1.25 (1.04–1.50) |
| > 100 | 193/1473 (13.1) | 2.05 (1.67–2.52) | 1.53 (1.22–1.91) |
| Don’t know/not stated | 162/2378 (6.8) | 1.01 (0.82–1.25) | 1.02 (0.82–1.28) |
| Smoking status | |||
| Never tried, not susceptible | 364/11 075 (3.3) | 1.0 (ref) | 1.0 (ref) |
| Never tried, susceptible | 562/4719 (11.9) | 3.95 (3.44–4.53) | 3.86 (3.36–4.43) |
| Puffer | 523/1624 (34.3) | 15.08 (12.97–17.53) | 13.56 (11.60–15.85) |
| Past 30-day e-cigarette use | |||
| No | 1313/16 831 (7.8) | 1.0 (ref) | 1.0 (ref) |
| Yes | 136/487 (27.9) | 4.81 (3.90–5.94) | 2.12 (1.68–2.66) |
Note: CI = confidence interval, OR = odds ratio.
↵* Among those who had never smoked a whole cigarette at baseline, but had smoked a whole cigarette at follow-up; n = 1992 had already initiated smoking at baseline and were excluded from this measure.
↵† From separate generalized linear mixed models for initiating smoking between waves, including only the listed covariable, with school as a random effect (n = 17 318 for all models except race/ethnicity; n = 17 247 for race/ethnicity model).
↵‡ From a generalized linear mixed model for initiating smoking between waves, including the covariables in the table, with school (n = 86) as a random effect (n = 17 247).
↵§ Categories for age 17 and age ≥ 18 were combined because of low numbers for the latter category (n = 8).
↵¶ Information on race/ethnicity was missing for 71 participants; these were excluded from the multivariable model.