Income inequality and periodontal diseases in rich countries: an ecological cross-sectional study.

UNLABELLED

There are adverse effects of income inequality on morbidity and mortality. This relationship has not been adequately examined in relation to oral health.

AIMS

To examine the relationship between income inequality and periodontal disease in rich countries.

PARTICIPANTS

Adults aged 35-44 years in 17 rich countries with populations of more than 2 million.

METHODS

National level data on periodontal disease, income inequality and absolute national income were collected from 17 rich countries with populations of more than 2m. Pearson and partial correlations were used to examine the relationship between income inequality and percentage of 35-44-year-old adults with periodontal pockets > or = 4 mm and > or = 6 mm deep, adjusting for absolute national income.

RESULTS

Higher levels of income inequality were significantly associated with higher levels of periodontal disease, independently of absolute national income. Absolute income was not associated with levels of periodontal disease in these 17 rich countries.

CONCLUSION

Income inequality appears to be an important contextual determinant of periodontal disease. The results emphasise the importance of relative income rather than absoluteincome in relation to periodontal disease in rich countries.