Table 3.
Association of socio‐economic status (SES) and age with caries experience in deciduous and permanent teeth of children (5 and 8 yr of age) and young adults (14 yr of age and older): findings of Hurdle models
| Variable | Deciduous teeth | Permanent teeth† | ||
|---|---|---|---|---|
| OR for dmft > 0 (95% CI) | RR for caries experience (95% CI) | OR for DMFT > 0 (95% CI) | RR for caries experience (95% CI) | |
| SES (Low vs. High) | 1.66 (1.13–2.14)** | 1.55 (1.32–2.08)*** | 1.75 (1.41–2.16)*** | 1.47 (1.29–1.68)*** |
| Centred age (per yr) | 1.15 (1.14–1.51)*** | 1.31 (1.02–1.29)* | 1.22 (1.18–1.27)*** | 1.11 (1.08–1.15)*** |
| Centred age2 † | 1.00 (0.98–1.01) | 0.99 (0.98–1.00)* | ||
| Centred age × SES | 0.93 (0.74–1.14) | 0.92 (0.79–1.09) | 0.99 (0.93–1.06) | 1.01 (0.97–1.04) |
Age squared was significant, meaning that the association between age and caries experience for the count part was not lineair. Therefore age‐squared was used in the count model for a better fit.
*P < 0.05, **P < 0.01, ***P < 0.001.
†We included a quadratic term for centred age to achieve a better fit of the data with the model. RR, rate ratio.