There are also several limitations that need to be considered. First, despite the use of an active comparator and good propensity score balance achieved, residual confounding cannot be completely excluded. Furthermore, propensity score weighting does not ensure avoidance of collider stratification bias. Second, NHANES does not provide data differentiating on indication, duration, and dosage of benzodiazepine use. Although our study cannot differentiate between individuals newly initiating benzodiazepines and longer-term users, previous work has not found significant differences in hazards even after adjusting for higher dosage and prolonged exposure20 or duration of use.16 Nonetheless, because each participant is only assessed once, it is not possible to assess changing patterns of benzodiazepine use over time.
