Table 3 (Model 10) depicts odds of drug-related poisoning associated with benzodiazepine use, stratified by benzodiazepine dose and by buprenorphine co-use. Stratification on these variables allowed for observation of possible interaction effects between benzodiazepine dose and buprenorphine use. For high-dose benzodiazepines, poisoning odds associated with buprenorphine co-use were higher than would have been expected based on the assumption of additive risks (Wald Chi-Square= 4.02, p=0.045). Odds ratios associated with low- and high-dose benzodiazepine co-use with buprenorphine were respectively 1.11 (1.00–1.23) and 1.64 (1.39–1.93). Notably, these effects were lower than those for low- and high-dose benzodiazepines in absence of buprenorphine, which were respectively OR=1.69 (1.60–1.79) and OR=2.23 (2.04–2.45). In other words, individuals with OUD taking both buprenorphine and benzodiazepines had lower net-risk of poisoning than those taking benzodiazepines without buprenorphine.
