Table 1. Demographic characteristics of survey participants (N=8,762) and survey non-participants (N=16,749).

		Survey Participants		Survey Non-Participants		X2
		N	%	N	%
Sex	Male	4194	47.9	8496	50.7	18.18*
	Female	4568	52.1	8253	49.3
Age	50 - 54	2061	23.5	4606	27.5	71.48*
	55 - 59	2083	23.8	3966	23.7
	60 - 64	1991	22.7	3551	21.2
	65 - 69	1547	17.7	2481	14.8
	70 - 74	1080	12.3	2145	12.8
SEIFA1	Lower	2395	27.3	5652	33.7	190.48*
	Higher	6367	72.7	11097	66.3
Location	NSW	1805	20.6	4408	26.3	109.50*
	QLD	1634	18.6	2961	17.7
	SA	1843	21.0	2811	16.8
	VIC	1658	18.9	3629	21.7
	WA	1822	20.8	2940	17.6
Education2	Higher Education	5000	57.1	-	-
	School Only	3725	42.5	-	-
Employment3	Working	4679	53.4	-	-
	Other	4034	46.0	-	-

^*p<.001

¹SEIFA = Index of Relative Socio-economic Advantage and Disadvantage. Groups based on average Australian SEIFA score of 1000 points.

²‘Higher Education’ includes certificates, diplomas, bachelor degrees and all other post-school qualifications. Missing Values N=37.

³Working’ includes Full-Time and Part-Time. ‘Other’ includes retired, home duties, and unemployed. Missing Values N=49.

NOTE: Data unavailable for Survey Non-Participants for Education and Employment variables.