Fifth, NDI-linked NHANES data are not yet available for more recent years, limiting the study’s generalizability. As the opioid epidemic has evolved since 2015, the most current trends warrant further investigation. Sixth, the public-use NDI does not provide data on overdose or suicide-specific mortality. Despite this limitation, our focus on all-cause mortality has the advantage of avoiding misclassification and missing data that can occur in cause-specific mortality analyses. Furthermore, recent data24 suggest that nearly 90% of benzodiazepine-opioid cotreatment deaths were due to nonoverdose causes. Future studies will need to differentiate between benzodiazepine use and misuse while taking into account illicit drug use, which occurs frequently in patients using benzodiazepines, although preliminary data suggest that only 1.5% of patients with benzodiazepine prescriptions develop a substance use disorder.21
