Table 4.
Prevalence of depression in past year among current, former and never smokers stratified by gender (NSDUH, 2005–2013, aged 12+)
| Gender | 2005* | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | Linear Trend | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Prevalence of depression in past year stratified by gender (%, s.e.) | Unadjusted OR (95%CI) |
t-test (p-value) |
Adjusted ORb,c (95%CI) |
t-test (p-value) |
|||||||||
| Current smokersa | |||||||||||||
| Male (%) | 6.19 | 6.70 | 7.16 | 6.76 | 7.42 | 7.10 | 7.44 | 7.38 | 7.82 |
1.02 (1.01, 1.04) |
t=2.74 (0.0081) |
1.02 (1.01, 1.04) |
t=2.66 (0.0099) |
| s.e. | (0.42) | (0.45) | (0.55) | (0.44) | (0.49) | (0.47) | (0.50) | (0.45) | (0.61) | ||||
| Female (%) | 14.29 | 14.36 | 14.70 | 14.17 | 14.03 | 14.70 | 15.00 | 14.73 | 13.60 | 1.00 (0.99, 1.01) |
t=−0.08 (0.9392) |
1.00 (0.99, 1.02) |
t=0.69 (0.4913) |
| s.e. | (0.60) | (0.55) | (0.60) | (0.62) | (0.65) | (0.72) | (0.67) | (0.63) | (0.76) | ||||
| Differential time trend among current smokers: year as continuous × gender | F(1)=5.14(0.0270) | F(1)=3.84(0.0547) | |||||||||||
| Former smokers | |||||||||||||
| Male (%) | 3.78 | 3.50 | 3.65 | 3.31 | 4.68 | 4.36 | 3.79 | 4.22 | 4.42 |
1.03 (1.00, 1.05) |
t=2.09 (0.0413) |
1.03 (1.00, 1.06) |
t=2.59 (0.0122) |
| s.e. | (0.35) | (0.33) | (0.32) | (0.32) | (0.41) | (0.40) | (0.32) | (0.51) | (0.40) | ||||
| Female (%) | 7.03 | 6.68 | 8.53 | 8.28 | 7.83 | 8.06 | 8.35 | 7.42 | 8.79 |
1.02 (1.00, 1.04) |
t=2.22 (0.0304) |
1.03 (1.01, 1.05) |
t=3.05 (0.0034) |
| s.e. | (0.49) | (0.46) | (0.55) | (0.69) | (0.65) | (0.58) | (0.54) | (0.50) | (0.54) | ||||
| Differential time trend among former smokers: year as continuous × gender | F(1)=0.17(0.6793) | F(1)=0.17(0.6801) | |||||||||||
| Never smokers | |||||||||||||
| Male (%) | 3.41 | 3.78 | 3.21 | 4.03 | 2.99 | 3.77 | 3.70 | 3.85 | 3.88 | 1.01 (0.99, 1.04) |
t=1.18 (0.2412) |
1.02 (1.00, 1.04) |
t=1.71 (0.0930) |
| s.e. | (0.28) | (0.36) | (0.28) | (0.36) | (0.28) | (0.33) | (0.35) | (0.32) | (0.41) | ||||
| Female (%) | 6.28 | 5.49 | 5.73 | 6.13 | 5.89 | 5.84 | 5.82 | 7.56 | 6.73 |
1.02 (1.01, 1.04) |
t=3.37 (0.0013) |
1.03 (1.01, 1.04) |
t=3.63 (0.0006) |
| s.e. | (0.42) | (0.32) | (0.31) | (0.40) | (0.39) | (0.31) | (0.32) | (0.38) | (0.38) | ||||
| Differential time trend among never smokers: year as continuous × gender | F(1)=0.56(0.4572) | F(1)=0.19(0.6668) | |||||||||||
| Differential time trend: year as continuous × smoking (current vs. never smokers; current vs. former smokers among each gender category |
Unadjusted | Adjusted | |||||||||||
| Differential time trend among male: year × smoking (current vs. never smokers) | F(1)=0.62(0.4347) | F(1)=0.12(0.7281) | |||||||||||
| Differential time trend among female: year × smoking (current vs. never smokers) | F(1)=6.18(0.0157) | F(1)=4.74(0.0335) | |||||||||||
| Differential time trend among male: year × smoking (current vs. former smokers) | F(1)=0.02(0.8837) | F(1)=0.21(0.6489) | |||||||||||
| Differential time trend among female: year × smoking (current vs. former smokers) | F(1)=3.28(0.0752) | F(1)=3.55(0.0644) | |||||||||||
Logistic regressions were applied to examine the time trend within each particular group. An odds ratio greater/less than one indicated a significant trend for the prevalence of depression among each smoking category stratified by gender to increase/decrease during 2005–2013, and t tests showed the significance of time trends.
who smoked in the past 12 months
Odds ratios are for past year depression versus no past year depression.
Adjusted models: were adjusted for age (12–17, 18–25, 26–34, 34–49, 50+ or older) & income (<$20,000, $20,000–$74,999, >=$75,000).
2005 as a reference year
s.e. - standard error
CI, confidence interval; NSDUH, National Survey on Drug Use and Health; OR, odds ratio; s.e., standard error