Secondary (passive/secondhand) smoking exposure during childhood vs No secondary smoking exposure: Early childhood caries (ECC) - incidence/risk
- Population
- Preschool children aged <=71 months (caries outcome assessed at 3-6 years)
- Intervention
- Secondary (passive/secondhand) smoking exposure during childhood
- Comparison
- No secondary smoking exposure
- Outcome
- Early childhood caries (ECC) - incidence/risk
Children exposed to secondary smoking from infancy have a higher incidence of early childhood caries by age 3 (RR 1.45; low certainty).
What each review found
Include earlier review versions| Finding | Effect | Studies | GRADE certainty |
|---|---|---|---|
Secondary (passive/secondhand) smoking exposure during childhood vs No secondary smoking exposure Caries incidence (early childhood caries) · Preschool children aged <=71 months (caries outcome assessed at 3-6 years) · Caries incidence by age 3 years (exposure from infancy, 4-18 months), Population-based birth cohorts (Japan), Overall Children exposed to secondary smoking from infancy have a higher incidence of early childhood caries by age 3 (RR 1.45; low certainty). Secondary Smoking and Early Childhood Caries: A Systematic Review and Meta-Analysis. (2025) All outcomes | RR 1.45 [1.41, 1.49] | 2 studies · 102,830 participants | Low |
Findings are shown side by side, never pooled across reviews.
The reviews
| Review | Searched up to | Included studies | AMSTAR 2 |
|---|---|---|---|
| Secondary Smoking and Early Childhood Caries: A Systematic Review and Meta-Analysis. 2025 All outcomes | 20 June 2024 | 16 | Not applicable |
Studies behind the findings
The primary studies the full-text reviews tie to this outcome. Reviews with headline outcomes only do not list them here.
- Secondhand smoke and incidence of dental caries in deciduous teeth among children in Japan: population based retrospective cohort study. · 2015 · included by 1 of these review
- The influence of lifestyle on the incidence of dental caries among 3-year-old Japanese children. · 2014 · included by 1 of these review
How reviews are matched to this question
Reviews word the same question differently. Four decision models (TypeSafe's Jev, Liquid AI's d1-ultra, SubQ Snap and Baseten's Elephant) judged each wording of the population, intervention, comparator and outcome against the others; two wordings count as the same when at least three of them agree and none clearly disagrees, and findings count as this question only when all four elements match. Timing, setting and subgroup never split a question: they are shown on each finding.