On the bias of estimates of influenza vaccine effectiveness from test-negative studies.

ABSTRACT: Estimates of the effectiveness of influenza vaccines are commonly obtained from a test-negative design (TND) study, where cases and controls are patients seeking care for an acute respiratory illness who test positive and negative, respectively, for influenza infection. Vaccine effectiveness (VE) estimates from TND studies are usually interpreted as vaccine effectiveness against medically-attended influenza (MAI). However, it is also important to estimate VE against any influenza illness (symptomatic influenza (SI)) as individuals with SI are still a public health burden even if they do not seek medical care. We present a numerical method to evaluate the bias of TND-based estimates of influenza VE with respect to MAI and SI. We consider two sources of bias: (a) confounding bias due to a (p

SUBMITTER: Ainslie KEC 

PROVIDER: S-EPMC5712239 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature