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. Author manuscript; available in PMC: 2020 Mar 28.
Published in final edited form as: Vaccine. 2019 Mar 2;37(14):1987–1993. doi: 10.1016/j.vaccine.2019.02.036

Table 5.

Bias of TN-bases estimates of VE when first week of vaccination varies.

Source of Biasa Outcome of Interest jv QB(5)b QB(50) QB(95) QAB(50) QAB(95)
None Symptomatic Influenza & Medically-Attended Influenza 1c 0.00 0.00 0.00 0.00 0.00
6 0.05 0.05 0.05 0.05 0.05
11 0.10 0.10 0.10 0.10 0.10
15 0.05 0.05 0.05 0.05 0.05
20 −0.03 −0.03 −0.03 0.03 0.03
24 −0.04 −0.04 −0.04 0.04 0.04
28 −0.03 −0.03 −0.03 0.03 0.03
33 −0.05 −0.05 −0.05 0.05 0.05
38 −0.07 −0.07 −0.07 0.07 0.07
A Symptomatic Influenza & Medically-Attended Influenza 1 −0.24 0.00 0.14 0.08 0.24
6 −0.14 0.05 0.17 0.08 0.18
11 −0.16 0.09 0.25 0.12 0.26
15 −0.18 0.04 0.19 0.09 0.22
20 −0.24 −0.03 0.09 0.06 0.24
24 −0.16 −0.04 0.04 0.05 0.16
28 −0.13 −0.03 0.04 0.04 0.13
33 −0.25 −0.05 0.08 0.07 0.25
38 −0.26 −0.07 0.05 0.08 0.26
B1 Symptomatic Influenza & Medically-Attended Influenza 1 0.00 0.01 0.03 0.01 0.03
6 0.05 0.06 0.07 0.06 0.07
11 0.10 0.10 0.12 0.10 0.12
15 0.05 0.06 0.07 0.06 0.07
20 −0.03 −0.02 −0.01 0.02 0.03
24 −0.04 −0.04 −0.03 0.04 0.04
28 −0.03 −0.03 −0.02 0.03 0.03
33 −0.04 −0.04 −0.03 0.04 0.04
38 −0.07 −0.07 −0.06 0.07 0.07
B2 Symptomatic Influenza & Medically-Attended Influenza 1 −0.02 −0.01 0.00 0.01 0.02
6 0.03 0.04 0.05 0.04 0.05
11 0.07 0.09 0.09 0.09 0.09
15 0.02 0.04 0.05 0.04 0.05
20 −0.05 −0.04 −0.03 0.04 0.05
24 −0.05 −0.05 −0.04 0.05 0.05
28 −0.04 −0.03 −0.03 0.03 0.04
33 −0.06 −0.05 −0.05 0.05 0.06
38 −0.10 −0.08 −0.08 0.08 0.10
BS Symptomatic Influenza & Medically-Attended Influenza 1 0.00 0.00 0.00 0.00 0.00
6 0.05 0.05 0.05 0.05 0.05
11 0.10 0.10 0.10 0.10 0.10
15 0.05 0.05 0.05 0.05 0.05
20 −0.03 −0.03 −0.03 0.03 0.03
24 −0.04 −0.04 −0.04 0.04 0.04
28 −0.03 −0.03 −0.03 0.03 0.03
33 −0.05 −0.05 −0.05 0.05 0.05
38 −0.08 −0.08 −0.07 0.08 0.08
Cd Symptomatic Influenza 1 0.01 0.07 0.16 0.07 0.16
6 0.05 0.11 0.18 0.11 0.18
11 0.10 0.17 0.26 0.17 0.26
15 0.06 0.12 0.21 0.12 0.21
20 −0.02 0.03 0.11 0.03 0.11
24 −0.04 0.00 0.05 0.02 0.05
28 −0.03 0.00 0.04 0.02 0.04
33 −0.04 0.02 0.09 0.03 0.09
38 −0.07 −0.01 0.07 0.04 0.07
Medically-Attended Influenza 1 0.00 0.00 0.00 0.00 0.00
6 0.03 0.04 0.05 0.04 0.05
11 0.06 0.08 0.09 0.08 0.09
15 0.03 0.04 0.05 0.04 0.05
20 −0.03 −0.02 −0.02 0.02 0.03
24 −0.04 −0.03 −0.02 0.03 0.04
28 −0.03 −0.02 −0.02 0.02 0.02
33 −0.04 −0.04 −0.03 0.04 0.04
38 -0.07 −0.06 −0.04 0.06 0.07
D Symptomatic Influenza & Medically-Attended Influenza 1 0.00 0.00 0.00 0.00 0.00
6 0.05 0.05 0.05 0.05 0.05
11 0.10 0.10 0.10 0.10 0.10
15 0.05 0.05 0.05 0.05 0.05
20 −0.03 −0.03 −0.03 0.03 0.03
24 −0.04 −0.04 −0.04 0.04 0.04
28 −0.03 −0.03 −0.03 0.03 0.03
33 −0.05 −0.05 −0.05 0.05 0.05
38 −0.08 −0.08 −0.07 0.08 0.08
a

Sources of bias: A - vaccination affects the probability of non-influenza ARI, B1 - Frail persons have a higher probability of non-influenza ARI compared to healthy persons, B2 – Frail persons have a higher probability of influenza ARI compared to healthy persons, BS - Frail persons have a higher probability of non-influenza and influenza ARI compared to healthy persons, and health status has the same effect on the probabilities of both types of ARI, C - Vaccination lowers the probability of seeking medical care in influenza ARI patients (because of reduced symptom severity), and D - ARI patients with low health awareness have a lower probability of seeking medical care compared to persons with high health awareness. Bias = estimated VE - true VE. The sign of bias indicates the direction of the difference between the estimated and true VE. A negative sign corresponds to underestimation while a positive bias indicates overestimation,

b

QB (5)=5th quantile of bias, QB (50)=50th quantile (median) of bias, QB (95)=95th quantile of bias, QAB (50)=50th quantile (median) of the absolute bias, QAB (95)=95th quantile of the absolute bias. Quantiles were determined from 1000 Monte Carlo simulations.

c

All vaccinated individuals are vaccinated in the first week of the study

d

Under bias C, bias of estimates of VE against symptomatic influenza and medically-attended influenza differ.