Unmeasured confounding is always a concern. Negative control variables (negative control exposure is correlated with the primary exposure or the confounder but does not causally affect the outcome of interest) can be used to correct for unmeasured confounding.
What this adds:
A new estimator that can be used to assess whether results are impacted by the existence of unmeasured confounding. This estimator does not have anything comparable currently implemented in zEpid.
Unmeasured confounding is always a concern. Negative control variables (negative control exposure is correlated with the primary exposure or the confounder but does not causally affect the outcome of interest) can be used to correct for unmeasured confounding.
What this adds:
A new estimator that can be used to assess whether results are impacted by the existence of unmeasured confounding. This estimator does not have anything comparable currently implemented in zEpid.
Reference:
https://arxiv.org/pdf/1808.04945.pdf