Abstract

Background: The extent to which different welfare states are associated with different health outcomes, we examined associations of welfare state and oral health quality-of-life in four wealthy countries. We hypothesized that targeting the poor is associated with greater income inequality in oral health quality-of-life than providing earnings-related benefits to all citizens.

Methods: Data were from nationally representative surveys in the United Kingdom (n=4064), Finland (n=5078), Germany (n=1454,) and Australia (n=2292) conducted from 1998–2002. The typology of Korpi and Palme classifies these countries into four welfare states. In each survey, subjects answered 14 questions of the Oral Health Impact Profile (OHIP-14) questionnaire which evaluates the adverse consequence of dental conditions on quality-of-life. For each country, survey estimation commands were used to create linear regression models that estimated the slope of the gradient between four quartiles of income and OHIP-14 severity scores. Parameter estimates for income gradients were contrasted across countries using Wald chi-square tests specifying a critical P-value of 0.008, equivalent to a Bonferroni correction of P<0.05 for the six pairwise tests.

Results: Statistically significant income gradients in OHIP-14 severity scores were found in all countries except Germany. A global test confirmed a significant cross-national difference in the magnitude of income gradients. In Australia, where a flat rate of benefits targeted the poor, the mean OHIP severity score reduced by 1.7 units (95% confidence interval: -2.15, -1.34) with each increasing quartile of household income, a significantly steeper gradient than in other countries.

Conclusion: The coverage and generosity of welfare state benefits appear to influence levels of inequality in population oral health quality-of-life.