Is the association between social support and oral health modified by household income? Findings from a national study of adults in Australia

OBJECTIVE

To investigate whether the association between social support and oral health outcomes is modified by levels of household income.

METHODS

Data were from the National Study of Adults Oral Health (NSAOH 2004-06), a nationally representative study comprising n = 3619 adults in Australia. Effect measure modification (EMM) analysis was adopted to verify whether the association between social support and poor/fair self-rated oral health, lack of a functional dentition (<21 teeth) and low Oral Health Related Quality of Life (OHRQoL; measured using OHIP-14) varies according to levels of income. Poisson regressions adjusted for age, sex, education, country of birth, main language spoken at home and remoteness were used to estimate prevalence ratios (PR) for oral health outcomes for each stratum of social support (overall, family, friends and significant other) and income (effect modifier). We then computed the Relative Excess Risk due to Interaction (RERI), which represents the risk that is over what would be expected if the combination of low social support and low income was entirely additive. Sensitivity analyses for different cut-offs of household income were performed.

RESULTS

Adults with lower levels of social support had a 2.1, 1.2 and 1.9 times higher prevalence of fair/poor self-rated oral health, <21 teeth and poor OHRQoL respectively. The RERIs observed were 0.98 (95% CI -0.01; 1.96) for poor/fair self-rated oral health; 0.52 (95% CI -0.06; 1.10) for lack of a functional dentition and 0.50 (95% CI -0.16; 1.15) for poor OHRQoL. For all outcomes and all individual domains of social support, the positive RERIs indicated that the joint association of low social support and low household income surpassed the sum of their separate associations with objective and subjective oral health indicators.

CONCLUSION

Individuals with lower levels of social support had poorer oral health than those with high levels of social support, although this association was small for the outcome <21 teeth. The association between social support and poor oral health indicators is modified by levels of household income. Hence, the provision of social support had a stronger association with the oral health of low-income participants, suggesting that socioeconomically disadvantaged individuals would mostly benefit from a social support intervention.

Social support and dental caries experience: Findings from the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study

OBJECTIVE

To examine the association of social support with dental caries experience in Hispanics/Latinos living in the United States (US) and to assess whether the relationship is modified by nativity status.

METHODS

This cross-sectional study analysed data for 4459 dentate men and women aged 18-74 years in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Sociocultural Ancillary Study. At baseline (2008-2011), dentists quantified dental caries experience as the number of decayed, missing, and filled permanent tooth surfaces (DMFS) for all teeth excluding third molars. Social support was assessed according to measures of structural support (Social Network Index) and functional support (Interpersonal Support Evaluation List). Covariate-adjusted multiple linear regression estimated the relationship between social support and dental caries experience and tested whether the association was modified by nativity status (born within the 50 US states, foreign-born <10 years in the United States, foreign-born >10 years or more in the United States).

RESULTS

In covariate-adjusted models, each additional role in the social network was associated with 1.39 fewer DMF tooth surfaces (95% CI: -2.21, -0.58) among foreign-born Hispanics/Latinos with fewer than 10 years lived in the US. For foreign-born Hispanics/Latinos with 10 years or more in the United States, each additional social network role was associated with 0.57 fewer DMF tooth surfaces (95% CI: -1.19, 0.04). No association was observed between functional social support and dental caries experience regardless of nativity status.

CONCLUSIONS

Our findings suggest that structural social support is protective against dental caries experience among recent immigrants of Hispanic/Latino background. This association may reflect the importance of social support to integration into the medical and dental infrastructure and thus receipt of dental care. Future research that examines the behavioural and cultural factors that moderate the relationship between social support and dental caries experience will inform development of culturally sensitive dental caries prevention programs for Hispanics/Latinos in the United States.

Pathways influencing dental caries increment among children: A cohort study

BACKGROUND

Dentists should assess pathways influencing the increment of dental caries among children to guide the prevention and treatment of the disease.

AIM

Evaluate the pathways that influence the increment of carious lesions in pre-school children.

DESIGN

This is a 2-year cohort study was conducted with a random sample of 639 pre-school children in southern Brazil. Caries experience, socioeconomic status (SES), social capital, and psychosocial characteristics were obtained at baseline. Increment of dental caries was assessed at 2 years follow-up in 467 children (cohort retention rate of 73.1%). Previously calibrated examiners assess the caries through the International Caries Detection and Assessment System (ICDAS). Structural equation modeling (SEM) was performed to test the pathways influencing dental caries increment.

RESULTS

Dental caries at baseline was heavily influenced by children's age (SC: 0.381, P < .01), tooth plaque (SC: 0.077, P = .02), parent's perception child oral health (SC: 0.295, P < .01), and household (SC: 0.148, P < .01). Increment of dental caries was directly affected by dental caries at baseline (Standardized Coefficients [SC]: 0.377, P < .01). Indirect paths were not significant.

CONCLUSIONS

Dental caries experience was the main factor of direct influence on the increment of caries, reinforcing the theory of risk accumulation over time.

Oral clinical status and oral health-related quality of life: is socioeconomic position a mediator or a moderator?

AIM

To evaluate whether socioeconomic position exerts a mediating and/or moderating effect on the association between oral clinical measures and oral health-related quality of life (OHRQoL) in adolescents.

MATERIALS AND METHODS

The study analysed data on 5,445 adolescents aged 15-19 years from the Brazilian Oral Health Survey (SBBrasil Project). The numbers of decayed and missing teeth, number of sextants with gingivitis and malocclusion were assessed through oral clinical examinations. Participant's age, sex, OHRQoL and socioeconomic position were also collected. Monthly family income was used to indicate the participant's socioeconomic position, and OHRQoL was assessed using the Oral Impacts on Daily Performance. Moderation was tested using Poisson regression models. Structural equation modelling and Sobel's test assessed the mediation effects.

RESULTS

Oral clinical measures, OHRQoL and socioeconomic position were significantly correlated (P < 0.001). The moderator effect of socioeconomic position on the association between all oral clinical measures and OHRQoL was observed. The impact of all oral clinical conditions on adolescents' OHRQoL was lower in the low-family-income groups compared with those with a better income. Socioeconomic position partially mediated the relationship between the four oral clinical measures and OHRQoL. Sobel's test confirmed these findings (P < 0.001).

CONCLUSIONS

The findings suggest the importance of socioeconomic position as a moderator and mediator factor between oral clinical measures and OHRQoL. Disadvantaged adolescents are likely to experience poor OHRQoL due to oral conditions. The reduction of the impact of oral conditions on quality of life in adolescents may be enhanced by addressing social inequalities related to oral health.