. Author manuscript; available in PMC: 2022 Sep 1.

Published in final edited form as: J Surv Stat Methodol. 2021 Jun;9(3):449–476. doi: 10.1093/jssam/smz050

Table 6.

Comparison of the 2016 National Internet Flu Survey (NIFS) Influenza Vaccination Estimates with the 2016 National Health Interview Survey (NHIS) Kaplan-Meier Influenza Vaccination Estimates

Subgroups^a	NIFS		NHIS October^b		NHIS November^c
	n	% (SE)	n	% (SE)	n	% (SE)

Overall	4,305	40.6(0.9)	2,612	29.6(1.1)^*	2,407	38.4(1.3)
Age (years)
18–49	1,494	34.3(1.4)	1,275	21.5(1.4)^*	1,072	27.1(1.7)^*
50–64	1,378	41.7(1.5)	624	32.0(2.3)^*	651	43.9(2.5)
≥65	1,433	56.6(1.4)	713	49.8(2.3)^*	684	59.9(2.3)
Race/ethnicity
White, non-Hispanic	2,511	39.7(1.1)	1,814	31.5(1.3)^*	1,727	43.0(1.6)
Black, non-Hispanic	673	40.6(2.2)	255	24.3(3.4)^*	232	25.5(3.7)^*
Hispanic	604	43.5(2.3)	329	21.7(2.7)^*	275	28.9(3.2)^*
Other, non-Hispanic	517	43.1(2.8)	214	37.9(4.6)	173	36.3(4.4)
High-risk (HR) medical condition, 18–64
18–64 year, HR	905	43.5(1.9)	366	35.4(3.1)^*	382	42.8(3.1)
18–64 year, no HR	1,967	34.0(1.2)	1,530	22.1(1.3)^*	1,338	30.2(1.6)
Sex
Male	2,137	39.5(1.3)	1,191	24.6(1.6)^*	1,090	34.8(1.8)^*
Female	2,168	41.7(1.2)	1,421	34.2(1.5)^*	1,317	41.5(1.8)
Employment
Employed	2,349	37.8(1.2)	1497	25.1(1.4)^*	1,365	33.7(1.6)^*
Unemployed	225	32.0(3.8)	83	17.5(5.0)^*	72	11.5(5.4)^*
Marital Status
Married	2,492	42.7(1.1)	1,143	33.6(1.6)^*	1,134	43.1(1.8)
Never Married	715	35.2(2.2)	630	20.2(2.3)^*	445	25.2(2.9)^*
Household Income
<$35,000	1,040	38.2	893	25.6(1.8)^*	775	29.1(2.2)^*
≥$75,000	1,777	42.4	768	33.7(2.1)^*	771	43.9(2.3)

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

A subset of the categories is shown for certain subgroups for brevity.

Influenza vaccination coverage estimate is calculated using the Kaplan-Meier method. For the NHIS November estimates, the calculation includes respondents vaccinated by October 31, 2016 and interviewed during November 2016 (respondents who were vaccinated in November were censored).

Influenza vaccination coverage estimate is calculated using the Kaplan-Meier method. For the NHIS December estimates, the calculation includes respondents vaccinated by November 30, 2016, and interviewed during December 2016.

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