TABLE 4.

Interaction Between Benzodiazepine or Z-drug and Opioid Prescription on the Risk of an Adverse Postoperative Outcome

Benzodiazepine or Z-drug Prescription in the 90 Days Before Surgery	Opioid Prescription in the 90 Days Before Surgery	Total N	N (%) Meeting Composite Outcome	Unadjusted OR (95% CI)	Adjusted OR (95% CI)
No	No	490,738	9933 (2.02%)	Reference
Yes	No	41,520	981 (2.36%)	1.17 (1.10–1.25)	1.07 (0.99–1.14)
No	Yes	199,721	5541 (2.77%)	1.38 (1.34–1.43)	1.23 (1.19–1.28)
Yes	Yes	53,367	2030 (3.80%)	1.91 (1.82–2.01)	1.45 (1.37–1.53)

Measure of interaction on the multiplicative scale: OR 1.1 (95% CI 1.01–1.20) P= 0.02.

ORs adjusted for age, sex, race/ethnicity, surgical procedure, comorbidities, opioid prescription, antidepressant prescription.