Comparison of “ever” and “OTC” NRT users versus non-users
| “Ever” NRT use | “OTC” NRT use | |||||||
|---|---|---|---|---|---|---|---|---|
| Sample size | Used NRT (%) | Unadjusted p value OR (95% CI) | Adjusted p value* OR (95% CI) | Sample Size | Used NRT (%) | Unadjusted p value OR (95% CI) | Adjusted p value* OR (95% CI) | |
| p Values shown are the logistic regression omnibus test of association between all levels of the row variable and NRT use. Odds ratios are pairwise comparisons between category and referent category (initial level where p value noted) from logistic regression. When the confidence limits for the odds ratio do not include 1.0, this indicates that the row category differed significantly in NRT use in comparison to the reference category for that variable. | ||||||||
| *Logistic regression: adjusted for covariates of age (continuous), sex (dichotomised), education (categorical), smoking rate (continuous), and first cigarette within 30 minutes of waking (dichotomised). | ||||||||
| FTND, Fagerstrom test for nicotine dependence; NDSS, nicotine dependence syndrome scale. | ||||||||
| Overall sample | 6839 | 39.7 | – | – | 3448 | 25.2 | – | – |
| Demographic characteristics | ||||||||
| Age (years) | ||||||||
| 18–25 (referent) | 457 | 27.6 | <0.001 | – | 352 | 12.1 | <0.001 | – |
| 26–35 | 980 | 35.6 | 1.45 (1.22 to 1.72) | – | 588 | 19.4 | 1.75 (1.34 to 2.28) | – |
| 36–45 | 1718 | 44.5 | 2.10 (1.78 to 2.48) | – | 857 | 33.2 | 3.60 (2.79 to 4.64) | – |
| 46–55 | 1642 | 45.6 | 2.20 (1.85 to 2.62) | – | 731 | 34.5 | 3.81 (2.90 to 5.01) | – |
| 56+ | 2042 | 42.2 | 1.91 (1.60 to 2.30) | – | 920 | 31.7 | 3.37 (2.53 to 4.49) | – |
| Sex | ||||||||
| Female (referent) | 4354 | 38.2 | <0.011 | – | 2191 | 23.1 | <0.006 | – |
| Male | 2464 | 41.2 | 1.14 (1.03 to 1.25) | – | 1247 | 27.1 | 1.24 (1.07 to 1.43) | – |
| Education | ||||||||
| Non-HS graduate (referent) | 701 | 32.4 | <0.001 | – | 422 | 18.7 | <0.001 | – |
| High school (HS) graduate | 2324 | 37.9 | 1.27 (1.07 to 1.52) | – | 1179 | 23.7 | 1.35 (1.04 to 1.75) | – |
| Some college | 2230 | 39.9 | 1.39 (1.17 to 1.65) | – | 1112 | 25.3 | 1.48 (1.14 to 1.91) | – |
| Associate degree | 602 | 48.7 | 1.99 (1.59 to 2.47) | – | 283 | 31.9 | 2.04 (1.47 to 2.84) | – |
| Bachelor degree | 640 | 44.7 | 1.69 (1.35 to 2.10) | – | 300 | 34.3 | 2.28 (1.65 to 3.14) | – |
| Postgraduate degree | 310 | 43.5 | 1.61 (1.20 to 2.16) | – | 134 | 25.7 | 1.51 (0.94 to 2.42) | – |
| Annual household income | ||||||||
| Under $15000 (referent) | 1403 | 34.5 | <0.001 | – | 807 | 21.1 | <0.001 | – |
| $15000–$24999 | 1026 | 34.8 | 1.02 (0.85 to 1.21) | – | 540 | 21.7 | 1.04 (0.80 to 1.34) | – |
| $25000–$39999 | 1452 | 36.4 | 1.09 (0.93 to 1.27) | – | 728 | 23.4 | 1.14 (0.90 to 1.44) | – |
| $40000–$59999 | 1458 | 42.8 | 1.42 (1.22 to 1.66) | – | 692 | 29.2 | 1.54 (1.23 to 1.94) | – |
| $60000+ | 1500 | 47.1 | 1.70 (1.46 to 1.97) | – | 681 | 29.9 | 1.60 (1.27 to 2.00) | – |
| Smoking status and history | ||||||||
| Cigarettes per day | ||||||||
| 10 or less (referent) | 1624 | 29.7 | <0.001 | – | 947 | 13.6 | <0.001 | – |
| 11–14 | 373 | 36.4 | 1.35 (1.07 to 1.71) | – | 198 | 22.2 | 1.81 (1.26 to 2.60) | – |
| 15–20 | 2807 | 41.8 | 1.71 (1.50 to 1.94) | – | 1356 | 27.7 | 2.42 (1.97 to 2.98) | – |
| 21–30 | 1280 | 46.8 | 2.08 (1.79 to 2.42) | – | 614 | 35.8 | 3.53 (2.79 to 4.48) | – |
| 31+ | 717 | 46.4 | 2.06 (1.71 to 2.47) | – | 317 | 34.5 | 3.34 (2.50 to 4.46) | – |
| Daily smoking | ||||||||
| No (referent) | 445 | 23.8 | <0.001 | <0.001 | 275 | 10.0 | <0.001 | <0.008 |
| Yes | 6394 | 41.0 | 2.22 (1.80 to 2.73) | 1.50 (1.19 to 1.90) | 3173 | 26.7 | 3.27 (2.27 to 4.70) | 1.73 (1.16 to 2.57) |
| Years of smoking | ||||||||
| 10 or less (referent) | 641 | 27.0 | <0.001 | <0.001 | 489 | 12.7 | <0.001 | <0.001 |
| 11–20 | 1152 | 36.9 | 1.58 (1.35 to 1.85) | 1.59 (1.33 to 1.91) | 641 | 20.9 | 1.82 (1.43 to 2.32) | 1.70 (1.29 to 2.23) |
| 21–30 | 1789 | 45.9 | 2.29 (1.97 to 2.67) | 2.52 (1.99 to 3.19) | 872 | 34.6 | 3.65 (2.89 to 4.60) | 3.57 (2.48 to 5.16) |
| 31–40 | 1549 | 47.1 | 2.41 (2.04 to 2.86) | 2.87 (2.08 to 3.97) | 678 | 35.7 | 3.83 (2.95 to 4.97) | 3.91 (2.36 to 6.48) |
| 41+ | 1647 | 42.6 | 2.00 (1.67 to 2.40) | 3.18 (2.04 to 4.95) | 743 | 33.4 | 3.45 (2.60 to 4.57) | 4.80 (2.38 to 9.68) |
| Number of quit attempts | ||||||||
| 0–2 (referent) | 2353 | 32.6 | <0.001 | <0.001 | 958 | 25.4 | <0.364 | <0.435 |
| 3–5 | 2196 | 39.5 | 1.35 (1.20 to 1.53) | 1.38 (1.21 to 1.56) | 1158 | 25.1 | 0.99 (0.82 to 1.19) | 0.96 (0.79 to 1.17) |
| 6–10 | 1255 | 44.5 | 1.66 (1.44 to 1.91) | 1.69 (1.46 to 1.96) | 717 | 23.2 | 0.89 (0.72 to 1.11) | 0.84 (0.67 to 1.05) |
| 11+ | 1035 | 49.5 | 2.03 (1.75 to 2.36) | 2.00 (1.71 to 2.34) | 615 | 27.3 | 1.11 (0.89 to 1.38) | 0.99 (0.79 to 1.26) |
| Smoking dependence | ||||||||
| FTND | ||||||||
| 1 or less (referent) | 866 | 23.5 | <0.001 | <0.001 | 513 | 10.5 | <0.001 | <0.001 |
| 1<FTND⩽3 | 1413 | 33.9 | 1.67 (1.39 to 2.01) | 1.83 (1.48 to 2.25) | 739 | 19.2 | 2.03 (1.49 to 2.76) | 1.92 (1.36 to 2.73) |
| 3<FTND⩽5 | 2103 | 41.9 | 2.35 (1.98 to 2.79) | 2.74 (2.12 to 3.55) | 1031 | 27.5 | 3.24 (2.43 to 4.31) | 2.97 (1.95 to 4.52) |
| 5<FTND⩽7 | 1483 | 47.5 | 2.94 (2.46 to 3.53) | 3.57 (2.67 to 4.77) | 694 | 33.3 | 4.25 (3.15 to 5.73) | 3.74 (2.34 to 5.98) |
| 7<FTND | 686 | 54.0 | 3.82 (3.09 to 4.72) | 5.04 (3.56 to 7.12) | 330 | 43.7 | 6.62 (4.76 to 9.20) | 5.91 (3.44 to 10.16) |
| Time to first cigarette | ||||||||
| After 60 minutes (referent) | 904 | 24.0 | <0.001 | – | 541 | 10.3 | <0.001 | – |
| 31–60 minutes | 964 | 35.6 | 1.74 (1.44 to 2.12) | – | 484 | 19.9 | 2.16 (1.56 to 2.99) | – |
| 6–30 minutes | 3013 | 41.3 | 2.22 (1.89 to 2.61) | – | 1497 | 27.4 | 3.28 (2.49 to 4.32) | – |
| Within 5 minutes | 1908 | 48.0 | 2.92 (2.46 to 3.46) | – | 899 | 35.1 | 4.71 (3.54 to 6.26) | – |
| NDSS-T | ||||||||
| −3 or less (referent) | 573 | 20.9 | <0.001 | <0.001 | 326 | 11.7 | <0.001 | <0.001 |
| −3<NDSS⩽−1.5 | 1211 | 31.5 | 1.75 (1.38 to 2.21) | 1.65 (1.29 to 2.11) | 618 | 14.2 | 1.25 (0.85 to 1.86) | 0.98 (0.65 to 1.48) |
| −1.5<NDSS⩽0 | 1331 | 38.2 | 2.35 (1.86 to 2.96) | 2.15 (1.68 to 2.75) | 666 | 24.3 | 2.42 (1.68 to 3.50) | 1.82 (1.23 to 2.68) |
| 0<NDSS⩽1.5 | 1213 | 43.8 | 2.96 (2.35 to 3.73) | 2.75 (2.14 to 3.53) | 592 | 28.2 | 2.97 (2.06 to 4.29) | 2.26 (1.52 to 3.36) |
| 1.5<NDSS | 1602 | 52.2 | 4.15 (3.31 to 5.19) | 3.73 (2.89 to 4.82) | 776 | 38.6 | 4.75 (3.34 to 6.77) | 3.28 (2.20 to 4.90) |
| Craving (at last quit) | ||||||||
| Not present/mild (1,2; referent) | 1919 | 31.0 | <0.001 | <0.001 | 1006 | 18.7 | <0.001 | <0.011 |
| Moderate (3) | 2568 | 40.8 | 1.53 (1.35 to 1.73) | 1.36 (1.20 to 1.55) | 1327 | 25.8 | 1.51 (1.25 to 1.83) | 1.25 (1.02 to 1.53) |
| Severe (4) | 2214 | 46.9 | 1.96 (1.73 to 2.23) | 1.63 (1.42 to 1.87) | 1078 | 30.3 | 1.89 (1.55 to 2.29) | 1.38 (1.12 to 1.71) |
| Withdrawal (at last quit) | ||||||||
| 1.3 or less (referent) | 1141 | 21.2 | <0.001 | <0.001 | 584 | 10.6 | <0.001 | <0.001 |
| 1.3<WD⩽2 | 2058 | 34.6 | 1.97 (1.66 to 2.34) | 1.93 (1.62 to 2.31) | 1048 | 20.3 | 2.15 (1.60 to 2.89) | 2.14 (1.57 to 2.90) |
| 2<WD⩽3 | 2195 | 46.4 | 3.22 (2.72 to 3.81) | 3.06 (2.57 to 3.65) | 1135 | 30.1 | 3.63 (2.73 to 4.84) | 3.38 (2.50 to 4.57) |
| 3<WD | 1310 | 53.4 | 4.26 (3.55 to 5.12) | 3.96 (3.25 to 4.81) | 644 | 37.8 | 5.13 (3.79 to 6.95) | 4.42 (3.20 to 6.11) |
| Difficulty in quitting | ||||||||
| 2 or less (referent) | 564 | 20.4 | <0.001 | <0.001 | 266 | 10.4 | <0.001 | <0.001 |
| 2<Diff⩽5 | 1002 | 24.9 | 1.29 (1.00 to 1.67) | 1.24 (0.95 to 1.61) | 530 | 9.8 | 0.94 (0.59 to 1.50) | 0.88 (0.55 to 1.43) |
| 5<Diff⩽7 | 1055 | 27.2 | 1.46 (1.14 to 1.86) | 1.40 (1.09 to 1.80) | 586 | 13.1 | 1.30 (0.84 to 2.01) | 1.24 (0.79 to 1.95) |
| 7<Diff⩽9 | 2128 | 43.0 | 2.93 (2.34 to 3.68) | 2.70 (2.13 to 3.41) | 1043 | 26.9 | 3.18 (2.13 to 4.75) | 2.71 (1.79 to 4.11) |
| 9<Diff⩽10 | 2090 | 56.8 | 5.12 (4.07 to 6.44) | 4.52 (3.56 to 5.74) | 1023 | 45.0 | 7.06 (4.73 to 10.53) | 5.62 (3.70 to 8.52) |
| Medical and psychiatric history | ||||||||
| Smoking related disease | ||||||||
| Not reported (referent) | 2259 | 38.5 | <0.001 | <0.005 | 1170 | 23.0 | <0.001 | <0.225 |
| Reported | 3028 | 45.2 | 1.32 (1.18 to 1.47) | 1.19 (1.05 to 1.34) | 1475 | 29.7 | 1.41 (1.20 to 1.67) | 1.12 (0.93 to 1.35) |
| Psychiatric condition | ||||||||
| Not reported (referent) | 1222 | 38.1 | <0.006 | <0.001 | 595 | 25.1 | <0.511 | <0.121 |
| Reported | 4065 | 42.8 | 1.22 (1.06 to 1.40) | 1.30 (1.13 to 1.51) | 2050 | 26.5 | 1.07 (0.87 to 1.33) | 1.20 (0.95 to 1.51) |