TABLE 5

Sensitivity Analysis for VE Estimates With Adjustments to Case and Comparison Cohort Vaccination Status

Sensitivity AnalysisNo. Flu-Related Deaths% Cases VaccinatedAverage % Vaccinated (LCL, UCL)VE95% CI
NIS-Flu comparison cohortNIS-Flu cohorta
 Excluding deaths with unknown vaccination status2912648 (42, 55)6554 to 74
 Treating deaths with unknown vaccination status as unvaccinated3582149 (42, 55)7466 to 80
 Assuming 10% underestimationb2912653 (46, 59)7264 to 79
 Assuming 10% overestimationb2912644 (38, 49)5644 to 67
 Assuming 20% overestimationb2912639 (34, 44)4629 to 59
NHIS high-risk cohortNHIS high-risk cohortc
 Excluding deaths with unknown vaccination status1533147 (37, 57)5131 to 67
 Treating deaths with unknown vaccination status as unvaccinated1822647 (37, 56)6247 to 73
 Assuming 10% underestimationb1533152 (41, 62)6144 to 73
 Assuming 10% overestimationb1533142 (34, 51)4116 to 59
 Assuming 20% overestimationb1533137 (30, 45)27−4 to 50
NHIS no high-risk cohortNHIS no high-risk cohortc
 Excluding deaths with unknown vaccination status1352040 (38, 43)6547 to 78
 Treating deaths with unknown vaccination status as unvaccinated1671640 (38, 43)7360 to 83
 Assuming 10% underestimationb1352044 (41,47)7156 to 81
 Assuming 10% overestimationb1352036 (34, 39)5835 to 73
 Assuming 20% overestimationb1352032 (30, 34)4924 to 68
MarketScan high-risk cohortMarketScan high-risk cohortc
 Excluding deaths with unknown vaccination status153313518−17 to 42d
 Treating deaths with unknown vaccination status as unvaccinated18226353812 to 56d
MarketScan no high-risk cohortMarketScan no high-risk cohorte
 Excluding deaths with unknown vaccination status1352028384 to 60d
 Treating deaths with unknown vaccination status as unvaccinated16716275024 to 67d
  • LCL, lower 95% confidence limit; UCL, upper 95% confidence limit; CI, credible interval.

  • a Average coverage estimate for NIS-Flu cohort paired with pediatric death by season, age group, state of residence, and month preceding illness onset.

  • b Survey coverage estimates for each comparison cohort were increased by 10% or reduced by 10% or 20%.

  • c Average national coverage estimate for NHIS and MarketScan comparison cohorts paired with pediatric death by season, age group, high-risk status, and month preceding illness onset.

  • d 95% confidence intervals for VE from logistic regression with odds of vaccination in MarketScan comparison cohort entered as an offset.

  • e For children without high-risk conditions, state-specific coverage estimates were used for MarketScan comparison cohorts paired with pediatric death by season, age group, and month preceding illness onset.