Table 3

Measures of educational inequality as defined by SII and RII for smoking, diabetes, obesity and physical inactivity by gender in NI and RoI for available survey years and trend over time

			1997	2001	2005/2006	2010/2011	Trend*		1998	2002	2007	Trend*
			Northern Ireland						Republic of Ireland
Males	Smoking	SII	32.7	38.7	33.5	36.2	0.90	SII	24.1	18.7	22.8	0.92
	Smoking	RII	2.4	4	3.8	4.5	0.01	RII	2.0	2.1	2.1	0.64
	Diabetes	SII†	2.3	2.9	3.3	4.8	0.18	SII	−0.8	2.2	N/A	0.01
	Diabetes	RII	2.4	2.4	2.5	2.5	0.90	RII	0.3	3.2	N/A	0.01
	Obesity	SII	−6.6	N/A	7.5	2.3	0.09	SII	6.9	21.3	8.3	0.73
	Obesity	RII	0.8	N/A	1.4	1.1	0.36	RII	1.7	3.2	1.5	0.29
	Physical inactivity	SII	N/A	10.7	32.6	20.2	0.13	SII	16.5	27.7	12.8	0.63
	Physical inactivity	RII	N/A	1.3	2.0	1.8	<0.01	RII	1.3	1.5	1.2	0.65
Females	Smoking	SII	35.5	35	37.4	34.8	0.95	SII	27.6	27.5	27.3	0.69
	Smoking	RII	3.5	3.5	4.6	4.2	0.14	RII	2.2	3.9‡	2.8‡	0.02
	Diabetes	SII†	2.2	3.3	2.5	3.7	0.18	SII	2.1	3.4	N/A	0.54
	Diabetes	RII	2.9	8.8	2.3	2.4	0.37	RII	7.4	8.9	N/A	0.71
	Obesity	SII	6.3	N/A	12.7	16.2	0.61	SII	16.0	28.2	6.9	<0.01
	Obesity	RII§	1.5	N/A	1.6	2.1	0.90	RII	4.2	8.2	1.7	<0.01
	Physical inactivity	SII	N/A	21.1	30.9	12.9	0.12	SII§	23.3	20.2	16.5‡	0.33
	Physical inactivity	RII	N/A	1.5	1.9	2.4‡	0.92	RII§	1.4	1.3	1.3‡	0.56

*Test for trend in SII/RII (significant difference in SII/RII if p value of ridit × survey year interaction term <0.05).
†Model fitted using Ordinary Least Squares regression with robust SEs22 due to non-convergence of generalised linear model with identity function.
‡Significant gender difference in SII/RII in survey year (♀ significantly greater inequality in females—p value of ridit×gender interaction term <0.05).
§Significant gender difference in SII/RII over time (♀ significantly greater inequality in females—p value of ridit×gender×survey year interaction term <0.05).
N/A, not available; NI, Northern Ireland; RII, Relative Index of Inequality (rate ratio); RoI, the Republic of Ireland; SII, Slope Index of Inequality (rate difference).