Inequality, Familial Aggregation, and Risk Prediction of Caries in Siblings.

Area of Science:

• Dental Public Health
• Epidemiology
• Social Determinants of Health

Background:

• Social and family conditions significantly impact dental health, yet evidence on familial aggregation of caries among adolescent siblings is limited.
• Social and family-level factors have not been evaluated as isolated predictors of caries at the individual level.

Purpose of the Study:

• To evaluate socioeconomic patterning of caries among siblings.
• To assess sibling-specific aggregation of caries within families and its variation by parental socioeconomic position (SEP).
• To examine the predictive ability of sibling caries, SEP, and other social/familial factors for caries in cosiblings.

Main Methods:

• Nationwide Danish register-based study of 15-year-olds (index siblings) and their biological siblings (cosiblings).
• Data compiled from national dental, social, and population registers; caries measured by DMFS index.
• Analysis included negative binomial regression for SEP-caries associations, alternating logistic regressions for familial aggregation, and classification and regression tree (CART) for prediction.

Main Results:

• Significant socioeconomic patterning of caries observed among adolescent siblings.
• Significant sibling-specific aggregation of caries found; cosiblings of affected index siblings had 3.9 times higher odds of caries.
• Sibling similarity in caries was stronger in socioeconomically disadvantaged families.
• Index sibling caries was the most important predictor of caries in cosiblings (predicted in ≥84% of cases).

Conclusions:

• Caries in one sibling warrants family-based preventive approaches targeting cosiblings.
• Sibling caries level is a crucial predictor for identifying at-risk children.
• Integrating social and family data can target prevention efforts to reduce caries inequalities.