Table 7.

Comparison of the 2016 National Internet Flu Survey (NIFS) Estimates with the 2016 Behavioral Risk Factor Surveillance System (BRFSS) Kaplan-Meier Estimates

Subgroupsa	NIFS		BRFSSb		NIFS – BRFSS
	n	% (SE)	n	% (SE)	% (SE)
Overall	4,305	40.6(0.9)	16,445	26.6(0.8)	14.0(1.2)*
Age (years)
18–49	1,494	34.3(1.4)	5,105	18.4(1.1)	15.9(1.8)*
50–64	1,378	41.7(1.5)	4,886	29.7(1.6)	12.0(2.2)*
≥65	1,433	56.6(1.4)	6,454	43.3(1.4)	13.3(2.0)*
Race/ethnicity
White, non-Hispanic	2,511	39.7(1.1)	12,814	28.7(0.9)	11.0(1.4)*
Black, non-Hispanic	673	40.6(2.2)	1,209	25.2(3.4)	15.4(4.1)*
Hispanic	604	43.5(2.3)	1,159	20.8(2.3)	22.7(3.2)*
Other, non-Hispanic	517	43.1(2.8)	980	22.7(2.6)	20.4(3.9)*
High-risk (HR) medical condition, 18–64 years only
18–64 year, HR	905	43.5(1.9)	2,704	30.7(2.2)	12.8(3.0)*
18–64 year, no HR	1,967	34.0(1.2)	7,196	19.4(0.9)	14.6(1.5)*
Sex
Male	2,137	39.5(1.3)	6,821	23.7(1.2)	15.8(1.7)*
Female	2,168	41.7(1.2)	9,622	29.2(1.0)	12.5(1.6)*
Employment
Employed	2,349	37.8(1.2)	7,653	21.5(0.9)	16.3(1.5)*
Unemployed	225	32.0(3.8)	562	21.0(4.4)	11.0(5.8)
Marital Status
Married	2,492	42.7(1.1)	8627	28.8(1.1)	13.9(1.6)*
Never married	715	35.2(2.2)	2,368	20.7(1.8)	14.5(2.8)*
Household Income
<$35,000	1,040	38.2(1.8)	5,296	24.4(1.5)	13.8(2.4)*
≥$75,000	1,777	42.4(1.4)	4,385	27.3(1.3)	15.1(1.9)*

Note.—% = weighted vaccination coverage estimate; SE, weighted standard error.

^aA subset of the categories is shown for certain subgroups for brevity.

^bInfluenza vaccination coverage estimate is calculated using the Kaplan-Meier method. For the BRFSS, the calculation includes respondents interviewed October 29 through November 12, 2016, and vaccinated prior to the interview date.

^*p < 0.05 by t-test (comparing against NIFS).