Table 4.
Adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) for dental caries in relation to smoking in the household of 20,703 schoolchildren, RYUCHS, Japan
| Deciduous subgroup (n = 13,872) | Permanent subgroup (n = 20,253) | |
|---|---|---|
| Adjusted PR1 (95% CI) | Adjusted PR1 (95% CI) | |
| Decayed and/or filled teeth | ||
| Smoking in household | ||
| Never | 1.00 | 1.00 |
| Former | 1.02 (0.99, 1.06) | 1.03 (1.00, 1.06) |
| Current <152 | 1.04 (1.02, 1.06) | 1.05 (1.02, 1.07) |
| Current ≥152 | 1.06 (1.04, 1.08) | 1.03 (1.00, 1.06) |
| P for trend | < 0.0001 | 0.01 |
| Pack-years of passive smoking in household | ||
| None | 1.00 | 1.00 |
| 0.1-2.9 | 1.03 (1.01, 1.06) | 1.05 (1.02, 1.08) |
| 3.0-6.9 | 1.05 (1.03, 1.07) | 1.02 (0.99, 1.05) |
| ≥7.0 | 1.05 (1.03, 1.08) | 1.04 (1.01, 1.07) |
| P for trend | <0.0001 | 0.006 |
| Decayed teeth | ||
| Smoking in household | ||
| Never | 1.00 | 1.00 |
| Former | 1.06 (1.00, 1.12) | 1.09 (1.01, 1.17) |
| Current <152 | 1.08 (1.04, 1.12) | 1.19 (1.13, 1.25) |
| Current ≥152 | 1.12 (1.07, 1.16) | 1.16 (1.10, 1.23) |
| P for trend | < 0.0001 | < 0.0001 |
| Pack-years of passive smoking in household | ||
| None | 1.00 | 1.00 |
| 0.1-2.9 | 1.04 (1.00, 1.09) | 1.12 (1.06, 1.20) |
| 3.0-6.9 | 1.12 (1.07, 1.17) | 1.18 (1.12, 1.26) |
| ≥7.0 | 1.11 (1.06, 1.16) | 1.17 (1.11, 1.24) |
| P for trend | <0.0001 | <0.0001 |
| Filled teeth | ||
| Smoking in household | ||
| Never | 1.00 | 1.00 |
| Former | 1.00 (0.95, 1.04) | 1.01 (0.96, 1.06) |
| Current <152 | 1.03 (1.00, 1.06) | 0.99 (0.96, 1.03) |
| Current ≥152 | 1.05 (1.01, 1.09) | 0.97 (0.93, 1.01) |
| P for trend | 0.003 | 0.19 |
| Pack-years of passive smoking in household | ||
| None | 1.00 | 1.00 |
| 0.1-2.9 | 1.04 (1.01, 1.07) | 1.02 (0.98, 1.07) |
| 3.0-6.9 | 1.02 (0.98, 1.05) | 0.96 (0.92, 1.00) |
| ≥7.0 | 1.04 (1.00, 1.08) | 0.99 (0.96, 1.03) |
| P for trend | 0.06 | 0.26 |
1 Adjustment for sex, age, region of residence, toothbrushing frequency, use of fluoride, sugar intake, and paternal and maternal educational level.
2 Number of cigarettes smoked in the household per day.