Were NZ's structural changes to the welfare state in the early 1990s associated with a measurable increase in oral health inequalities among children?

Objective: To test the hypothesis that the 1990-91 social and economic policy changes in New Zealand were associated with a subsequent increase in socioeconomic and ethnic inequalities in the dental caries experience of five-year-old children. Method: Dental caries data from the School Dental Service treating the greater Wellington area were analysed for the period 1995-2000. Multivariate models were developed for deciduous caries prevalence (logistic regression) and severity (negative binomial regression). Results: In the years 1995, 1996, 1997, 1998, 1999 and 2000, complete data were available for 2,627, 3,335, 4,404, 4,155, 3,154 and 2,804 children, respectively. Ethnic and socio-economic differences in caries prevalence and severity were substantial and persistent during the observation period. Where caries severity was concerned, there was a significant interaction between time and Maori ethnicity, indicating that (on average) the oral health of Maori children deteriorated in comparison to their European counterparts. Conclusions: The early-1990s social and economic policy changes were associated with an apparent widening of ethnic inequalities in caries severity among five-year-old children. Implications: Economic rationalism appears to have oral health disadvantages for non-European children. Before implementation of proposed major social and economic policy changes, policy-makers should consider their health implications.