Table 2.

Mean (SD) proportion of “don’t know” responses at baseline and follow-up by socio-demographic characteristics with bivariate test of change in proportion of “don’t know” responses by characteristic (N=444)

Characteristics	Baseline	Follow-up	Wald	p value
Overall	0.199 (.240)	0.155 (.179)	15.505	<0.001
Gender			0.093	0.761
Male	0.215 (.263)	0.168 (.192)
Female	0.185 (.219)	0.145 (.167)
Age Group			25.99	0.001
18 – 29	0.304 (.299)	0.181 (.212)
30 – 39	0.174 (.211)	0.135 (.155)
40 – 49	0.149 (.194)	0.123 (.145)
50 –59	0.145 (.187)	0.148 (.167)
60 +	0.142 (.164)	0.190 (.179)
Place of Birth			10.58	0.001
U.S.	0.299 (.275)	0.197 (.208)
Other	0.156 (.210)	0.137 (.161)
Marital Status			16.923	<0.001
Married	0.158 (.200)	0.149 (.169)
Other	0.292 (.295)	0.170 (.199)
Parental Status			15.04	<0.001
Parent	0.159 (.194)	0.145 (.164)
Not a parent	0.317 (.314)	0.183 (.215)
SES			4.42	0.035
Owns both house and car	0.172 (.201)	0.148 (.158)
Does not own house and car	0.229 (.275)	0.164 (.200)
Educational Level			10.34	0.001
< High school education	0.161 (.210)	0.147 (.163)
High school graduate/GED or above	0.249 (.268)	0.167 (.199)
Insurance Status			1.011	0.315
Any health insurance	0.207 (.236)	0.173 (.184)
No health insurance	0.182 (.246)	0.124 (.166)
Healthcare Use			0.235	0.628
Healthcare visit in past year	0.195 (.234)	0.154 (.173)
No healthcare visit in past year	0.228 (.283)	0.167 (.224)

Note: GEE adjustment with exchangeable covariance structure to account for clustering within the family looking at change from baseline to follow-up for each variable separately (i.e. bivariate associations).