Decomposing early and adult life social position effects on oral health and chronic diseases in a cross-sectional study of Southern Brazil

Objectives: As the socio-economic trajectory can influence on individual health during the life course, the aim of this study was to test a model of socio-economic life course effects on chronic diseases, tooth loss and on oral health-related quality of life using structural equation model (SEM) to decompose direct and indirect effects. Methods: This cross-sectional study was performed in southern Brazil, within public healthcare users with 18 years old or more (n = 433). Latent variables were the Oral Health Impact Profile (OHIP), Childhood Socio-economic Status (SESC) and Adulthood (SESA), and Chronic Diseases (CD), and observed variables were sex, age, smoking status and tooth loss. The statistical analysis was performed using structural equation modelling (SEM) using WLSMV estimator. For the final model, we kept only plausible significant paths with P < 0.30. Results: Final model presented an adequate fit: RMSA 0.03, Comparative Fit Index (CFI) 0.97, TLI 0.97, and Weighted Root Mean Square Residual (WRMR) 1.19. The direct effect from SESC to tooth loss was β = −0.08 (P = 0.19) and the indirect was β = −0.12 (P = 0.02). The indirect effect from SESC to OHIP was β = −0.14 (P = 0.01) and there is no direct effect. The direct effect from SESA to tooth loss was β = −0.21 (P < 0.01) and there is no indirect effect. The direct effect from SESA to OHIP was β = −0.14 (P = 0.05). The association of SESA on SESC was β = 0.59 (P < 0.01). Conclusions: SESC had indirect effects on OHIP and number of teeth via SESA, supporting the chain of effects theory, but not for chronic diseases.