Table 3.

Stated willingness to participate in health studies by demographic characteristics

	General population row %					Case-control study participants row %					Cohort study participants row %
	Number	Very unwilling/Unwilling	Neutral	Very willing/Willing	p valuea	Number	Very unwilling/Unwilling	Neutral	Very willing/ Willing	p valuea	Number	Very unwilling/Unwilling	Neutral	Very willing/Willing	p valuea
Whole group	1546	11	28	61		153	1	5	93		401	13	69	319
Male	653	12	30	58	0.047	93	2	2	96	0.182	375	3	65	297	0.469
Female	893	10	27	61		60	0	10	90		26	0	4	22
Age <40 years	428	12	36	52	<0.001	0	0	0	0	0.992	3	0	67	33	0.056
40–60 years	637	11	29	60		20	0	0	100		156	3	21	76
>60 years	475	10	20	70		132	2	6	92		241	3	14	83
ATSIb: Yes	22	18	18	64	0.967	3	0	0	100	0.643	3	0	67	33	0.059
No	1512	11	28	61		148	1	5	93		393	3	17	80
Country of birth
Australia	1181	11	27	61	0.495	107	1	7	93	0.511	285	3	18	79	0.483
Other	359	11	31	59		45	2	2	96		116	3	15	82
Highest level education
School	650	13	26	61	0.218	74	2.7	7	91	0.356	183	2	16	82	0.400
Technical/trade certificate	341	9	35	57		46	0	2	98		126	6	17	77
Tertiary	535	10	27	64		31	0	6	94		89	2	19	79
Other	10	10	20	70		0	0	0	0		0	0	0	0
Remoteness index
Metropolitan	870	11	30	59	0.291	94	1	6	93	0.373	272	4	17	79	0.680
Inner regional	345	12	24	64		43	2	5	93		98	3	18	79
Outer regional/Remote	331	11	28	62		16	0	0	100		31	0	16	84
SEIFA Relative Disadvantagec
Quintile 1 most disadvantaged	217	15	29	57	0.287	3	0	0	100	0.928	39	5	23	72	0.618
Quintile 2	312	9	29	62		20	0	5	95		73	1	8	90
Quintile 3	340	11	28	61		42	2	5	93		72	0	22	78
Quintile 4	293	10	31	59		33	3	6	91		97	6	19	75
Quintile 5 least disadvantaged	384	12	25	64		55	0	5	95		120	3	17	80
Previously done health survey Yes	384	6	21	73	<0.001	153	1	5	94	-	401	3	17	80	-
No	1107	13	30	57		0	0	0	0		0	0	0	0
Previously refused health survey  Yes	166	19	33	48	<0.001	11	0	9	91	0.585	38	5	18	76	0.501
No refusal	1329	10	27	63		135	0	5	95		355	3	17	81
Long-term disease/disability Yes	481	9	23	68	0.002	65	2	2	97	0.131	115	4	16	80	0.967
No	1150	12	30	59		85	1	8	91		278	3	18	80
Spontaneously raised privacy/health issue during interview Yes	19	26	21	53	0.245	2	0	0	100	0.708	5	20	40	40	0.021
No	1527	11	29	61		151	1	5	93		396	3	17	80

^aA chi squared test for trend was used for comparing the numbers for all variables except age, Remoteness index and SEIFA for which ordinal logistic regression was used

^b ATSI is the acronym for Aboriginal and Torres Strait Islander

^c SEIFA Socio-Economic Indexes for Areas is an aggregate score of relative socio-economic disadvantage; the lower the score the higher the relative disadvantage