IADR Abstract Archives
Income-related Inequality in Dental Service Use in Canada: 1994-2014
Objectives: To describe income-related inequality in dental service use in Canada from 1994 to 2014.
Methods: We used six nationally representative Canadian surveys: National Population Health Survey (NPHS) 1994/95, NPHS 1998/99, Canadian Community Health Survey (CCHS) cycle 2.1 2003, CCHS 2009-2010, and CCHS 2013-2014. The outcome of interest was dental service use in the past year. Income was measured as total household income adjusted for household size. We report age-standardised proportions and odds ratios for dental services use across five categories of income. Two summary measures of health inequality are used to investigate both absolute and relative inequalities: the slope index of inequality (SII) and the relative index of inequality (RII). We then investigated trends in inequality by comparing these estimates across the six surveys. These analyses were replicated for the ten Canadian provinces.
Results: Dental service use has increased from 56.7% in the NPHS 1994/95 to 67% in the CCHS 2013-2014 (P<0.001). There was a significant direct relationship between income level and dental service use in all six surveys (P<0.001). The SII declined from 0.43 in the NPHS 1994/95 to 0.41 in the CCHS 2013-2014; however, this decline was not significant (P=0.162). On the other hand, the RII declined significantly (P<0.001) from 2.18 in the NPHS 1994/95 to 1.82 in the CCHS 2013-2014. Data for the Canadian provinces suggests the presence of pro-rich inequalities in dental service use for all provinces across all surveys. Similar to the national pattern, the SII did not significantly change, whereas the RII declined in most provinces.
Conclusions: This study shows the continued presence of income-related inequalities in dental service use in Canada over twenty years. While absolute inequality remained steady, relative inequality decreased over this period.
Methods: We used six nationally representative Canadian surveys: National Population Health Survey (NPHS) 1994/95, NPHS 1998/99, Canadian Community Health Survey (CCHS) cycle 2.1 2003, CCHS 2009-2010, and CCHS 2013-2014. The outcome of interest was dental service use in the past year. Income was measured as total household income adjusted for household size. We report age-standardised proportions and odds ratios for dental services use across five categories of income. Two summary measures of health inequality are used to investigate both absolute and relative inequalities: the slope index of inequality (SII) and the relative index of inequality (RII). We then investigated trends in inequality by comparing these estimates across the six surveys. These analyses were replicated for the ten Canadian provinces.
Results: Dental service use has increased from 56.7% in the NPHS 1994/95 to 67% in the CCHS 2013-2014 (P<0.001). There was a significant direct relationship between income level and dental service use in all six surveys (P<0.001). The SII declined from 0.43 in the NPHS 1994/95 to 0.41 in the CCHS 2013-2014; however, this decline was not significant (P=0.162). On the other hand, the RII declined significantly (P<0.001) from 2.18 in the NPHS 1994/95 to 1.82 in the CCHS 2013-2014. Data for the Canadian provinces suggests the presence of pro-rich inequalities in dental service use for all provinces across all surveys. Similar to the national pattern, the SII did not significantly change, whereas the RII declined in most provinces.
Conclusions: This study shows the continued presence of income-related inequalities in dental service use in Canada over twenty years. While absolute inequality remained steady, relative inequality decreased over this period.