Table 1 Assessment of applicability of causal inference concepts to vaccine studies

Guignard et al., 2014 [8]

To assess whether diabetes is a risk factor for HZ

Matched cohort study in a US insurance claim database. Cox Proportional hazards regression

Analysis adjusted for age was applied to estimate the HR of developing HZ, including age, gender and co-morbidities as covariates

• Type II diabetes in subjects ≥65 years HR 3.12; 95% CI 2.77–3.52

• Type II diabetes in subjects 40–64 years HR 1.51; 95% CI 1.42–1.61

Cardiac disease and chronic pulmonary disease were also risk factors in non-diabetic subjects:

• Cardiac disease HR 1.92; 95% CI 1.73–2.13

• Chronic pulmonary disease HR 1.52; 95% CI 1.38–1.67

Str: N

Cons: N

Spe: N

Temp: Y

Biogr: N

Plau: Y

Coh: Y

Exp: N

Ana: N

Exch: N

Pos: Y

Cons: N

Willame et al., 2016 [9]

Risk of new onset autoimmune disease in 9–25-year-old women exposed to AS04-HPV-16/18 vaccine in the United Kingdom

Retrospective cohort study to assess the risk of autoimmune diseases in vaccinated and unvaccinated individuals (frequency matched for age and practice region) using a Poisson regression model

• IRR for “other autoimmune diseases” in the vaccinated and unvaccinated cohorts 1.41; 95% CI 0.86–2.31

Str: N

Cons: N

Spe: N

Temp: Y

Biogr: N

Plau: Y

Coh: N

Exp: N

Ana: N

Exch: N

Pos: Y

Cons: Y

Braeckman et al., 2012 [10]

Effectiveness of two doses of HRV in preventing hospitalization for rotavirus gastroenteritis in Belgium among children born after October 2006 and aged at least 14 weeks

Prospective, hospital-based, multicenter, matched case-control study. Percent VE = (1- OR)*100. OR calculated from a conditional logistic regression with 95% CI

• Unadjusted VE for two doses 90% (95% CI: 81–95).

• Unadjusted VE of at least one dose 91% (95% CI: 82–95)

Str: Y

Cons: Y

Spe: Y

Temp: Y

Biogr: N

Plau: Y

Coh: Y

Exp: Y

Ana: Y

Conditional Exch: likely

Pos: Y

Cons: Y