Letter to the Editor: Pulling Unmeasured Confounding Out by your Bootstraps: Too Good to be True?
Résumé
Inverse probability of treatment weighting can account for confounding under a number of assumptions, including that of no unmeasured confounding. A recent simulation study proposed a bootstrap bias correction, apparently demonstrating good performance in removing bias due to unmeasured confounding. We revisited the simulations, finding no evidence of bias reduction.